<?xml version="1.0" encoding="UTF-8"?><rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:sy="http://purl.org/rss/1.0/modules/syndication/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" > <channel> <title>quant – GMAT</title> <atom:link href="https://www.manhattanprep.com/gmat/blog/tag/quant/feed/" rel="self" type="application/rss+xml" /> <link>https://www.manhattanprep.com/gmat</link> <description>GMAT Prep Course, Best GMAT Class & Study Books | Manhattan Prep GMAT</description> <lastBuildDate>Fri, 08 Nov 2019 19:52:22 +0000</lastBuildDate> <language>en-US</language> <sy:updatePeriod> hourly </sy:updatePeriod> <sy:updateFrequency> 1 </sy:updateFrequency> <generator>https://wordpress.org/?v=6.3.2</generator> <item> <title>The Top 6 GMAT Quant Mistakes That You Don’t know You’re Making</title> <link>https://www.manhattanprep.com/gmat/blog/the-top-6-gmat-quant-mistakes-that-you-dont-know-youre-making/</link> <dc:creator><![CDATA[Chelsey Cooley]]></dc:creator> <pubDate>Tue, 16 Feb 2016 20:17:12 +0000</pubDate> <category><![CDATA[Fractions, Decimals, Percents]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[Problem Solving]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[fractions decimals percents]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[GMAT mistakes]]></category> <category><![CDATA[GMAT prep]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[gmat quant problem solving]]></category> <category><![CDATA[gmat study tips]]></category> <category><![CDATA[GMAT Tips]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[quant]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=11010</guid> <description><![CDATA[<p>Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! Check out our upcoming courses here. Sometimes, as you solve a GMAT Problem Solving problem, everything seems to go smoothly. You get an answer that matches one of the choices perfectly, […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-top-6-gmat-quant-mistakes-that-you-dont-know-youre-making/">The Top 6 GMAT Quant Mistakes That You Don’t know You’re Making</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><strong><em><img decoding="async" fetchpriority="high" class="alignleft size-full wp-image-11020" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-quant.png" alt="blog-quant" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-quant.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-quant-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" />Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Complete%20Courses%20Plug&utm_campaign=GMAT%20Blog">Check out our upcoming courses here</a>.</em></strong></p> <hr /> <p>Sometimes, as you solve a GMAT Problem Solving problem, everything seems to go smoothly. You get an answer that matches one of the choices perfectly, so you select it and move on to the next problem. But much later, when you’re reviewing the problem, you realize that you picked the wrong answer entirely. Why does this happen, and how can you stop it?</p> <p><span id="more-11010"></span></p> <p>According to data from GMAT Navigator, our online platform that lets students record their answers to GMAT practice problems (<a href="https://www.manhattanprep.com/gmat/store/online-resources/gmat-navigator/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Navigator%20-%201%20Year%20Access%20Plug&utm_campaign=GMAT%20Blog" target="_blank">click here for the premium version</a> or <a href="https://www.manhattanprep.com/gmat/store/online-resources/free-gmat-tracker-for-official-guides/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Navigator%20Basic%20-%20Free%20Plug&utm_campaign=GMAT%20Blog" target="_blank">here for the basic version</a>), there are certain Problem Solving problems that most students feel very confident about. Very few students guess on these problems. However, many students get these problems wrong, despite their high level of confidence. Here’s the list of mistakes these students make most frequently.</p> <ol> <li><strong>Off by 1: </strong>When a problem asks for a <em>largest</em> or <em>smallest</em> possible value, or when it includes inequalities, double-check your work before answering. The answer choices are often only 1 apart, and it’s easy to choose an answer that’s 1 too small or too large. For instance, what is the smallest integer that’s greater than 41/4? If you quickly divide 41 by 4 and take the integer part of the answer, 10, you’ll be off by</li> <li><strong>Off by 100: </strong>Be careful with percentage problems, especially ones with answer choices that are similar except for the number of decimal places (0.89, 8.9, 89, 890, etc.) If you miss the word ‘percent’ somewhere in a problem, or if you forget to multiply a decimal by 100 to convert it to a percent, your answer will be off by a factor of 100. <a href="https://www.manhattanprep.com/gmat/store/strategy-guides/fractions-decimals-and-percents/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=FractionsDecimalsPercentsGMATBlog&utm_campaign=GMAT%20Blog" target="_blank">Check out our guide to approaching percent problems</a> if you make this mistake.</li> <li><strong>Bad unit conversion</strong>: It’s easy to make a mistake when converting between kilometers and miles, dollars and cents, or grams and kilograms. The worst culprits are problems that ask you to convert between units you may not be familiar with, or even made-up units, since your instincts won’t tell you that your answer is wrong. Always write out the entire unit conversion and check your work carefully. It’s more time-consuming, but it’ll ensure you never multiply when you should divide, or accidentally convert the wrong value. <a href="https://www.manhattanprep.com/gmat/blog/2016/01/20/heres-how-to-do-gmat-unit-conversions-like-a-pro/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CCooley%20GMAT%20Unit%20Conversions%20Linkback%20From%20Top%206%20Quant%20Mistakes%20&utm_campaign=GMAT%20Blog" target="_blank">Read our guide to fast and safe unit conversions</a> to get a handle on this issue.</li> <li><strong>Missing the last step</strong>: You get all the way through the problem, doing all of the math correctly, and solve for the value of <em>n</em>. Then you choose that value and move on, never noticing that the problem <em>actually</em> asked you to choose the value of 2<em>n</em>, or <em>n</em><sup>2</sup>, as your answer. To avoid this, read the entire problem, and the answer choices, before you begin writing. Before you write anything else on your paper, jot down what you’re solving for and circle it.</li> <li><strong>Losing the units</strong>: Picture a rates & work problem that asks you to solve for the amount of <em>time</em> it would take two machines to complete a job when working together. Unbeknownst to you, one of the wrong answer choices is actually the <em>rate </em>at which the two machines are working, which is the <em>reciprocal</em> of the time. The answer choices don’t include units, so you have to keep track of them yourself. And be aware that the test writers might play dirty tricks with units in the text of a problem: for instance, rates are usually given in miles per hour, but I’ve seen a problem that includes a rate given in minutes per mile. Many of my students gloss right over the units, assume that the rate is written in miles per hour, and do all of the math correctly but get the wrong answer anyways. Don’t let that happen to you.</li> <li><strong>Percent more than/less than: </strong>120 is 20 percent more than 100, but 100<em> isn’t</em> 20 percent <em>less than</em> 120. (Take a moment to do the math, and figure out what number actually fits there!) You can’t switch back and forth between <em>percent more than</em> and <em>percent less than</em>, even if it seems to make the problem easier; the math just doesn’t work out. Make sure that when you translate a percent word problem into math, you’re keeping the same expressions as in the original problem.</li> </ol> <p>These issues were the six most common culprits that caused students to unknowingly miss GMAT Problem Solving questions. Learn them now, and double-check your work whenever you see a suspicious problem. There’s nothing wrong with missing a problem because you haven’t learned the math yet, but you never want to miss problems that you could easily have gotten right. ?</p> <p><strong>Want full access to Chelsey’s sage GMAT wisdom? Try the first class of one of <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CooleyCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/336">her upcoming GMAT courses</a> for absolutely free, no strings attached. </strong></p> <hr /> <p><em><strong><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/?utm_source=manhattanprep.com%2Fgre%2Fblog&utm_medium=blog&utm_content=CooleyBioGREBlog&utm_campaign=GRE%20Blog" target="_blank">Chelsey Cooley</a><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/?utm_source=manhattanprep.com%2Fgre%2Fblog&utm_medium=blog&utm_content=CooleyBioGREBlog&utm_campaign=GRE%20Blog" target="_blank"><img decoding="async" class="alignleft wp-image-10949 size-thumbnail" title="Chelsey Cooley Manhattan Prep GMAT Instructor" src="https://d27gmszdzgfpo3.cloudfront.net/gmat/wp-content/uploads/sites/18/2016/01/chelsey-cooley-150x150.png" alt="Chelsey Cooley Manhattan Prep GMAT Instructor" width="150" height="150" /></a> is a Manhattan Prep instructor based in Seattle, Washington.</strong> Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master’s degree in linguistics, a 790 on the GMAT, and a perfect 170/170 on the GRE. Check out Chelsey’s upcoming GMAT prep offerings <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CooleyCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/336">here</a>.</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-top-6-gmat-quant-mistakes-that-you-dont-know-youre-making/">The Top 6 GMAT Quant Mistakes That You Don’t know You’re Making</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>Decoding Divisibility and Primes on the GMAT – Part 1</title> <link>https://www.manhattanprep.com/gmat/blog/decoding-divisibility-and-primes-on-the-gmat-part-1/</link> <dc:creator><![CDATA[Stacey Koprince]]></dc:creator> <pubDate>Fri, 12 Feb 2016 22:16:10 +0000</pubDate> <category><![CDATA[Data Sufficiency]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[divisibility]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[GMAT Number Properties]]></category> <category><![CDATA[GMAT prep]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[how to study]]></category> <category><![CDATA[number properties]]></category> <category><![CDATA[Prime]]></category> <category><![CDATA[quant]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=11002</guid> <description><![CDATA[<p>Most of my students are driven crazy by GMAT Number Properties. On the face of it, the topic seems straightforward: I know what positive and negative, odd and even are. Divisibility stuff is a little more complicated, but come on: this was taught in school when we were 10! How hard can it be? Plenty […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/decoding-divisibility-and-primes-on-the-gmat-part-1/">Decoding Divisibility and Primes on the GMAT – Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" class="alignleft size-full wp-image-11003" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-decoding-pt1.png" alt="blog-decoding-pt1" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-decoding-pt1.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-decoding-pt1-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" />Most of my students are driven crazy by GMAT Number Properties. On the face of it, the topic seems straightforward: I know what positive and negative, odd and even are. Divisibility stuff is a little more complicated, but come on: this was taught in school when we were 10! How hard can it be?<span id="more-11002"></span></p> <p>Plenty hard, it turns out. The GMAT obviously can’t test you on what you were taught when you were 10; that’d be way too easy. So they have to find some way to make things conceptually harder—and they have definitely succeeded on Number Properties. (I secretly admire how good they are at testing NP, actually. I just don’t like to admit it.)</p> <p>So we’re going to dive into a series of NP problems to see how they mess with us. We’ll focus specifically on divisibility and prime, the topic that tends to be the most tricky. Try this GMATPrep® problem from the free exams and then we’ll talk!</p> <blockquote><p>“*If <i>x</i>, <i>y</i>, and <i>z</i> are integers greater than 1, what is the value of <i>x</i> + <i>y</i> + <i>z</i>?</p> <p>“(1) <i>xyz</i> = 70</p> <p>“(2) <img decoding="async" title="x/yz=7/10" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_985_5b25ea4c058dc2669fd83a5bd7efb25f.png" alt="x/yz=7/10" />”</p></blockquote> <p>Got your answer? Okay, first, let’s <i>understand</i> what’s going on.</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-1.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-103180" src="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-1.png" alt="Glance Read Jot" width="201" height="161" /></a></p> <p><i>Glance</i>: DS. Three variables. The question is a combo (that is, I don’t necessarily have to find the individual values for these variables). Maybe I’m going to have to test cases?</p> <p><i>Read</i>: Can’t do much with the question stem, besides writing down that info.</p> <p><i>Jot</i>:</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/12/339-image-1.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-112762" src="//static.blog.beatthegmat.com/mba/files/2015/12/339-image-1.png" alt="339 - image 1" width="368" height="288" /></a></p> <p>How should I approach this?</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-2.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-103186" src="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-2.png" alt="Reflect Organize" width="226" height="180" /></a></p> <p>Hmm. They’re all positive integers greater than 1. That’s intriguing; why greater than 1 and not the more common greater than 0? I’ll need to think about that.</p> <p>I just have to find the <i>sum</i> of the variables, not the individual variables. And each statement uses all three variables and provides some real numbers.</p> <p>So, the question is whether I can rearrange that info somehow to tell me the sum, even if it doesn’t tell me the individual variables. Let’s see.</p> <blockquote><p>“(1) <i>xyz</i> = 70”</p></blockquote> <p>If they’re all integers, then they have to be made up of the various possible factors of 70.</p> <p>Oh! This is key: they’re all integers <i>greater than 1</i>, so I can ignore the factor pair (1, 70). In other words, what I really care about is the prime factors of 70. I was wondering why they told me such a weird piece of info.</p> <p>Okay, so I need to break 70 down into its prime factors and then test cases with those numbers to see whether I get a definitive sum or multiple sums.</p> <p>70 = (7)(10) = (7)(2)(5)</p> <p>There are three variables…and three prime factors. So the three variables have to be 7, 2, and 5! The sum of those three numbers is always the same, regardless of the order in which the addition occurs. Statement (1) is sufficient to answer the question.</p> <blockquote><p>“(2) <img decoding="async" title="x/yz=7/10" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_985_5b25ea4c058dc2669fd83a5bd7efb25f.png" alt="x/yz=7/10" />”</p></blockquote> <p>(Remember, reflect first! Don’t just dive in.) Fractions are annoying, so I could try cross-multiplying. That would give me 10<i>x</i> = 7<i>yz</i>. That doesn’t actually look simpler (at least, not to me!), though.</p> <p>Oh, or how about this: <i>x</i> could be 7 and <i>yz</i> could be 10, in which case <i>y </i>and <i>z</i> have to be 2 and 5, in some order. That works! And those are the same numbers as in statement (1). Yay!</p> <p>But wait. Reflect some more. This is one possible solution, yes, but is it the <i>only</i> one?</p> <p>What if <i>x</i> = 14 and <i>yz</i> = 20? In that case, statement (2) is still true, but the values have changed. Will the sum be the same? No! It’ll be larger, since the values are larger.</p> <p>Statement (2) allows more than one possible sum, so it is not sufficient to answer the question.</p> <p>The correct answer is (A).</p> <p><img class="aligncenter" alt="" width="475" height="320" /></p> <p>Now, are you starting to see <i>how</i> the GMAT has found a way to make NP hard? The pure math that had to be done here wasn’t crazy hard. But the conceptual thinking was definitely not what we were taught in school. This is how they’re going to test your adult-level thinking of NP topics.</p> <h2>Key Takeaways for Divisibility and Primes on the GMAT:</h2> <p>(1) They’re not testing pure math here. They’re testing theory. You’re going to have to learn how to take Number Properties rules and think about them conceptually.</p> <p>(2) In order to do that, you’ll need to start picking up on the clues that they give in the way that they present the information. One key clue was that <i>integers greater than 1</i> piece coupled with multiplication later in the problem (in the statements). When you multiply integers greater than 1, those integers become factors of the larger number you create. This is your clue that you’re being asked about the factors of some number—and this puts you squarely in the category of Divisibility and Primes, one of the main topic areas under Number Properties. ???</p> <p>Want to learn more about the GMAT from Stacey? <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/86">Try one of her upcoming courses for free</a>.</p> <p>* GMATPrep® questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.</p> <p><strong>Keep Reading</strong>: <a href="https://www.manhattanprep.com/gmat/blog/decoding-divisibility-and-primes-on-the-gmat-part-2/">Part 2</a></p> <hr /> <p><em><strong><a href="https://www.manhattanprep.com/instructors/stacey-koprince/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceBioLinkGMATBlog&utm_campaign=GMAT%20Blog" target="_blank" rel="noopener"><img decoding="async" loading="lazy" class="alignleft" title="Stacey Koprince Manhattan Prep GMAT Instructor" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/stacey-koprince-150x150.png" alt="Stacey Koprince Manhattan Prep GMAT Instructor" width="150" height="150" /></a><a href="https://www.manhattanprep.com/instructors/stacey-koprince/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceBioLinkGMATBlog&utm_campaign=GMAT%20Blog">Stacey Koprince</a> is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.</strong> Stacey has been teaching the GMAT, GRE, and LSAT for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests. <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/86">Check out Stacey’s upcoming GMAT courses here</a>. As always, you can try your first class for free!</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/decoding-divisibility-and-primes-on-the-gmat-part-1/">Decoding Divisibility and Primes on the GMAT – Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>Two Minutes of GMAT Quant: A Breakdown – Part 1</title> <link>https://www.manhattanprep.com/gmat/blog/two-minutes-of-gmat-quant-a-breakdown-part-1-of-3/</link> <dc:creator><![CDATA[Emily Madan]]></dc:creator> <pubDate>Wed, 10 Feb 2016 23:04:54 +0000</pubDate> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Problem Solving]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[Taking the GMAT]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[GMAT First Glance]]></category> <category><![CDATA[gmat how to study]]></category> <category><![CDATA[GMAT prep]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[gmat strategies]]></category> <category><![CDATA[gmat study tips]]></category> <category><![CDATA[GMAT Tips]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[how to study]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[quant problem solving]]></category> <category><![CDATA[Working Backwards]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=10982</guid> <description><![CDATA[<p>Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! Check out our upcoming courses here. Two minutes is not a huge amount of time. Yet if you want to finish the entire GMAT Quant section in 75 minutes, two minutes […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/two-minutes-of-gmat-quant-a-breakdown-part-1-of-3/">Two Minutes of GMAT Quant: A Breakdown – Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10986" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-minutes-pt1.png" alt="blog-minutes-pt1" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-minutes-pt1.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/02/blog-minutes-pt1-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" /><strong><em>Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Complete%20Courses%20Plug&utm_campaign=GMAT%20Blog">Check out our upcoming courses here</a>.</em></strong></p> <hr /> <p>Two minutes is not a huge amount of time. Yet if you want to finish the entire GMAT Quant section in 75 minutes, two minutes is about all you have to solve each problem. Don’t interpret that to mean you just have to go quickly or skip important steps like checking your work. Instead, seek out a more efficient process for dealing with GMAT problems.</p> <p>Better yet, read along as I detail an efficient process for dealing with your two minutes.<span id="more-10982"></span></p> <p><strong>The First 5 Seconds: Glance</strong></p> <p>GMAT problems can be very helpful. They are full of hints that direct your process. The trick is knowing how to find those hints. For Problem Solving, start with a quick glance at the answer choices.You’re looking for two things: 1) Are the numbers arranged in any particular way that hints at what you’ll need to focus on and 2) Do the answer choices indicate any alternate strategies that might be helpful?</p> <p>If you find your focus in the answer choices, you’re at an incredible advantage. Take a look at these three sets of answers, each of which has a huge hint, to see if you can already spot them.</p> <p><strong>Set 1:</strong></p> <ol> <li>005</li> <li>05</li> <li>5</li> <li>5</li> <li>50</li> </ol> <p><strong>Set 2:</strong></p> <ol> <li>1/2 > M > 1/3</li> <li>1/3 > M >1/4</li> <li>1/4>M > 1/5</li> <li>1/5 > M > 1/10</li> <li>1/10 > M > 1/20</li> </ol> <p><strong>Set 3:</strong></p> <ol> <li>16%</li> <li>38%</li> <li>50%</li> <li>62%</li> <li>84%</li> </ol> <p>What did you see? Let’s look set-by-set.</p> <p><strong>Set 1:</strong> For Set 1, you should have noticed that each answer is 5*some power of 10. It’s only the decimal that moves. The hint is that you already know the numerical answer. It’s 5. What you don’t know is where the decimal should be, so that needs to be your focus when you dive into the problem.</p> <p><strong>Set 2:</strong> Set 2 is strikingly different. The problem will clearly ask you to solve for M, but the answers hint at a shortcut. Because M is given in a range, you shouldn’t need an exact value. Instead, if you can approximate it, you’ll be able to cut your time down.</p> <p><strong>Set 3:</strong> You’ll find many GMAT problems that ask for a percent value, as Set 3 does. The hint is that the answers contain not only the right answer, but also the trap answers. Imagine the problem asks you to solve for percent of x in a group of x’s and y’s. Imagine also that the percent of x is actually 62%, answer (D). Using perfectly accurate math, you solve the problem and determine that x = 62% and y = 38%. In the heat of the moment, you jump at the number you correctly solved for and pick 38%, answer (B). Perfect math, zero credit. (We call this kind of right-answer/wrong-answer relationship “Twins.” It’s pretty common.)</p> <p>So at this point you’re worried enough about falling for the trap, and you’re probably saying “The hint here is to be careful in my calculations? What kind of hint is that? I always have to careful, now I’m just more stressed about it.” Well said, you.</p> <p>We will never tell you the hint is to be more careful. That’s not helpful. Here’s the real hint: Your next step should be find a way to avoid the trap. The question asks you to solve for x, but don’t jump to that. Start my eliminating the trap answers. Two of the answer choices above 50%, two are below it, and one is exactly 50%. When comparing x and y, you have three options: x is greater, y is greater, or they are the same. If you can reason through the explanation and see that x must be greater than y, you can eliminate A, B, and C, knocking out the trap answers.</p> <p>The answer choices can also point toward alternate strategies. See if you can pick which ones in these examples:</p> <p><strong>Set 4:</strong></p> <ol> <li>x<sup>2</sup>–4</li> <li>(x – 2)<sup>2</sup></li> <li>x<sup>2</sup> / 4</li> <li>4x<sup>2</sup></li> <li>4 – x<sup>2</sup></li> </ol> <p><strong>Set 5:</strong></p> <ol> <li>1,200</li> <li>800</li> <li>600</li> <li>400</li> <li>200</li> </ol> <p><strong>Set 6:</strong></p> <ol> <li>10,635</li> <li>5,387</li> <li>1,382</li> <li>524</li> <li>23</li> </ol> <p>Each of these answers lets you know the problem can be solved indirectly. If you’re comfortable with our alternate strategies, hopefully you spotted at least two out of the three.</p> <p><strong>Set 4:</strong> Set 4 is perfect for smart numbers or testing cases, depending on the set up. Pick a value for x, plug in, and see which answer produces the desired answer.</p> <p><strong>Set 5:</strong> Set 5 sets you up for working backwards. The answers are easy to compute with, so start with the answers instead of the problem.</p> <p><strong>Set 6:</strong> Set 6 is less obvious. You shouldn’t try to work backwards with this one because those numbers would be ugly in computations. They’ll also probably be ugly to solve for. Here’s a crazy idea: Don’t worry about the actual answer. Each choice is drastically different from the others. Tackle this one by estimation. Should it be less than 10,000, but significantly higher than 1,000? B is your answer. Figuring that range out shouldn’t be too hard.</p> <p>This has been a rather long post and we’ve only made it through the first <em>five seconds</em> of your two minute time allocation.Check back soon for the next edition of the two-minute breakdown.</p> <p>More importantly, all of this analysis should take you only 5 seconds. Are you already comfortable with that? Probably not yet, but you can be. Open your OG to any problem solving page. Pick a problem. Do not solve. Cover up the actual problem and just examine the answer choices. Take your time and see what you can figure out. Then solve the problem using the hints and strategies you’ve already figured out. Keep practicing your analysis of answer choices, each time giving yourself a little less time. Once you can get a good hint or two from the answer choices in only 5-10 seconds, <a href="https://www.manhattanprep.com/gmat/blog/2016/02/19/two-minutes-of-gmat-quant-a-breakdown-part-2/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=EM%205%20-%20Two%20Minutes%20of%20GMAT%20Quant%3A%20A%20Breakdown%20Part%201%20Linkforward%20to%20Part%202&utm_campaign=GMAT%20Blog">you’re ready to focus on the next step</a>.</p> <hr /> <p><em><strong>Of course, the most in-depth way to learn the ins-and-outs of GMAT Quant is to <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Complete%20Courses%20Plug&utm_campaign=GMAT%20Blog">take a complete course</a> with one of our master instructors. Try out any first session for free! No strings attached.</strong></em></p> <hr /> <p><a href="https://www.manhattanprep.com/instructors/emily-madan/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Blog%20Emily%20Madan%20Instructor%20Bio&utm_campaign=GMAT%20Blog" target="_blank"><img decoding="async" loading="lazy" class="alignleft wp-image-10901 size-thumbnail" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/emily-madan-150x150.png" alt="Emily Madan Manhattan Prep GMAT Instructor" width="150" height="150" /></a><em><strong><a href="https://www.manhattanprep.com/instructors/emily-madan/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Blog%20Emily%20Madan%20Instructor%20Bio&utm_campaign=GMAT%20Blog" target="_blank">Emily Madan</a> is a Manhattan Prep instructor based in Philadelphia. </strong>Having scored in the 99th percentile of the GMAT (770) and LSAT (177), Emily is committed to helping others achieve their full potential. In the classroom, she loves bringing concepts to life and her greatest thrill is that moment when a complex topic suddenly becomes clear. <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Blog%20Emily%20Madan%20Upcoming%20Courses&utm_campaign=GMAT%20Blog#instructor/344">Check out Emily’s upcoming GMAT courses here</a>. Your first class is always free!</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/two-minutes-of-gmat-quant-a-breakdown-part-1-of-3/">Two Minutes of GMAT Quant: A Breakdown – Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>Three things to love about GMAT Roman numeral problems</title> <link>https://www.manhattanprep.com/gmat/blog/here-are-three-reasons-to-love-gmat-roman-numeral-problems/</link> <dc:creator><![CDATA[Chelsey Cooley]]></dc:creator> <pubDate>Mon, 11 Jan 2016 22:06:17 +0000</pubDate> <category><![CDATA[Data Sufficiency]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[Fractions, Decimals, Percents]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[GMAT Study Guide]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[data sufficiency]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[GMAT data sufficiency strategy]]></category> <category><![CDATA[GMAT roman numeral problems]]></category> <category><![CDATA[GMAT roman numeral problems strategy]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[how to study]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[roman numerals]]></category> <category><![CDATA[Strategy]]></category> <category><![CDATA[study plan]]></category> <category><![CDATA[study tips]]></category> <category><![CDATA[Tips]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=10862</guid> <description><![CDATA[<p>I. Roman numeral Quant problems aren’t a whole lot of fun. II. A lot of my students choose to skip them entirely, which is much smarter than wasting five minutes wondering what to do! III. However, it’s possible to turn this rare and tricky problem type into an opportunity. Read on, and learn why many […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/here-are-three-reasons-to-love-gmat-roman-numeral-problems/">Three things to love about GMAT Roman numeral problems</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10872" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-numerals.png" alt="blog-numerals" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-numerals.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-numerals-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" />I. Roman numeral Quant problems aren’t a whole lot of fun.</p> <p>II. A lot of my students choose to skip them entirely, which is much smarter than wasting five minutes wondering what to do!</p> <p>III. However, it’s possible to turn this rare and tricky problem type into an opportunity.</p> <p>Read on, and learn why many GMAT high-scorers love Roman numeral problems.<span id="more-10862"></span></p> <h4><strong>Reason 1: They’re always easier than they look.</strong></h4> <p>Roman numeral problems are a little bit like Data Sufficiency problems. The difficulty usually doesn’t come from the math itself; it comes from complicated logic and deliberately obscure writing. You should always start a tricky-looking Data Sufficiency problem by <em>translating</em> and <em>simplifying</em> the problem, and you can do the same on Roman numeral problems.</p> <p>Here’s a problem from the GMAC’s GMATPrep software.</p> <p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10864" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-problem.png" alt="Roman_Numeral_Problem" width="911" height="615" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-problem.png 911w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-problem-300x203.png 300w" sizes="(max-width: 911px) 100vw, 911px" /></p> <p>At first glance, this problem is a mess. If you simplify the problem before you begin approaching it, though, you’ll discover a much easier problem underlying it. Start with the question stem, just like in Data Sufficiency:</p> <p><img decoding="async" loading="lazy" class="size-full wp-image-10866 alignleft" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-inequality-1.png" alt="Roman_Numeral_Inequality_1" width="155" height="175" /></p> <p> </p> <p> </p> <p> </p> <p> </p> <p>Then, simplify the statements, starting with the first:</p> <p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10867" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-inequality-2.png" alt="Roman_Numeral_Inequality_2" width="307" height="316" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-inequality-2.png 307w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-inequality-2-291x300.png 291w" sizes="(max-width: 307px) 100vw, 307px" /></p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> <br /> The first statement actually simplifies to exactly what you’re given in the question itself, so it must be true. As an exercise, simplify the second statement in the same way. It simplifies to <em>ad </em>> <em>bc</em>, which <em>isn’t</em> true.</p> <p>At this point, you know that the right answer must include I, and it can’t include II. You could move on and simplify the third, much more complex statement, but do you really have to?</p> <h4><strong>Reason 2: There’s partial credit. </strong></h4> <p>Well, not technically. But take another look at those answer choices.</p> <p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10868" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-choices.png" alt="Roman_Numeral_Choices" width="261" height="319" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-choices.png 261w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-choices-245x300.png 245w" sizes="(max-width: 261px) 100vw, 261px" /></p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p>You can actually eliminate all but two of them. Only (B) and (E) meet the criteria of including Roman numeral I, but not including Roman numeral II. If you’re quick enough with algebra, you could get to this point 1 minute into the problem — and <strong>a 50/50 guess after 1 minute beats a definitive answer after 3 minutes</strong>, when it comes to maximizing your final score. Since Roman numeral problems often have one or two statements that are much simpler than the others, they represent a fantastic opportunity to take a <em>good</em> guess quickly.</p> <p>But if you’ve got plenty of time to solve a Roman numeral problem all the way through, what do you do?</p> <h4><strong>Reason 3: Testing easy cases works really well. </strong></h4> <p>I mentioned above that the difficulty of Roman Numeral problems doesn’t usually come from the math. When you test cases, you’ll rarely be tripped up by tough arithmetic or lengthy calculations. Plus, problems are often designed so that it’s clear what cases you should test. When they aren’t, you can sometimes get enough information by just testing a simple case at random. Try that approach with the third statement.</p> <p>Since <strong><em>ad < bc</em></strong>, choose the following values:</p> <p>a = 1 b = 2</p> <p>d = 1 c = 2</p> <p>Then, plug those values into statement III:</p> <p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10870" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/roman-numeral-fractions.png" alt="Roman_Numeral_Fractions" width="237" height="274" /></p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p>Since that isn’t true, statement III doesn’t <em>have</em> to be true. The correct answer to the problem is <strong>(B) I only</strong>. The thing to notice here is how straightforward it was to test that case — and how, unlike in Data Sufficiency, testing just one case sometimes gives you all the information you need.</p> <h4><strong>What to do next</strong></h4> <p>Roman numeral problems are rare on the GMAT. There’s no reason to spend hours studying them, since you might not see even a single one on any given Quant section. That said, they’re sometimes easier than they look! After reading this article, you have all of the basic tools you need to approach most Roman numeral problems. To test them out, try the following problems from the <strong>Official Guide to the GMAT, 2016</strong>: Problem Solving 66, 96, and 107.</p> <hr /> <p><em><strong><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/#" target="_blank"><img decoding="async" loading="lazy" class="alignleft wp-image-8513 size-thumbnail" src="//cdn2.manhattanprep.com/gre/wp-content/uploads/sites/19/2015/11/chelsey-cooley-150x150.jpg" alt="Chelsey-Cooley" width="150" height="150" /></a></strong></em><em><strong><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/?utm_source=manhattanprep.com%2Fgre%2Fblog&utm_medium=blog&utm_content=CooleyBioGREBlog&utm_campaign=GRE%20Blog">Chelsey Cooley</a> is a Manhattan Prep instructor based in Seattle, Washington.</strong> Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master’s degree in linguistics, a 790 on the GMAT, and a perfect 170/170 on the GRE. Check out Chelsey’s upcoming GMAT prep offerings <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CooleyCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/336">here</a>.</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/here-are-three-reasons-to-love-gmat-roman-numeral-problems/">Three things to love about GMAT Roman numeral problems</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>GMAT Story Problems: Draw It Out</title> <link>https://www.manhattanprep.com/gmat/blog/gmat-story-problems-draw-it-out/</link> <dc:creator><![CDATA[Stacey Koprince]]></dc:creator> <pubDate>Thu, 07 Jan 2016 21:45:24 +0000</pubDate> <category><![CDATA[Apps and Admissions]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[GMAT Study Guide]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[Problem Solving]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[gmat problem solving]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[gmat quant problem solving]]></category> <category><![CDATA[gmat study tips]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[how to study]]></category> <category><![CDATA[problem solving]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[quant problem solving]]></category> <category><![CDATA[study tips]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=10820</guid> <description><![CDATA[<p>Whenever I see a story problem, I immediately make myself think, “How would I solve this in the real world?” I don’t want to get sucked into doing a bunch of annoying textbook math. In the real world, we lay things out on paper very differently than when we’re in “I’m taking a math test” […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/gmat-story-problems-draw-it-out/">GMAT Story Problems: Draw It Out</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10821" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-drawout.png" alt="Blog-DrawOut" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-drawout.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2016/01/blog-drawout-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" />Whenever I see a story problem, I immediately make myself think, “How would I solve this in the real world?” I don’t want to get sucked into doing a bunch of annoying textbook math. In the real world, we lay things out on paper very differently than when we’re in “I’m taking a math test” mode.</p> <p>Want to see what I mean? Try this GMATPrep® problem from the free exams and then we’ll talk!<span id="more-10820"></span></p> <blockquote><p>“*Rates for having a manuscript typed at a certain typing service are $5 per page for the first time a page is typed and $3 per page each time a page is revised. If a certain manuscript has 100 pages, of which 40 were revised only once, 10 were revised twice, and the rest required no revisions, what was the total cost of having the manuscript typed?</p> <p>“(A) $430</p> <p>“(B) $620</p> <p>“(C) $650</p> <p>“(D) $680</p> <p>“(E) $770”</p></blockquote> <p>Got your answer? Okay, first, let’s <i>understand</i> what’s going on.</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-1.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-103180" src="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-1.png" alt="228 - Q Process 1" width="233" height="186" /></a></p> <p><i>Glance</i>: PS. Story problem. The answers are numeric and aren’t super easy but they aren’t too ugly, either.</p> <p><i>Read</i>: I’m trying to figure out how much it’s going to cost me to get my manuscript typed. (See what I did there? Real world.) There are various prices depending on the service required.</p> <p><i>Jot</i>:<a href="//static.blog.beatthegmat.com/mba/files/2015/10/331-image-1.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-110931" src="//static.blog.beatthegmat.com/mba/files/2015/10/331-image-1.png" alt="331 - image 1" width="340" height="123" /></a></p> <p>How should I approach this?</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-2.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-103186" src="//static.blog.beatthegmat.com/mba/files/2015/04/228-Q-Process-2.png" alt="228 - Q Process 2" width="235" height="188" /></a></p> <p>I could write out a formula here. But I <i>really</i> don’t want to. <img decoding="async" class="wp-smiley" src="//www.beatthegmat.com/mba/wp-includes/images/smilies/icon_smile.gif" alt=":)" /></p> <p>In the real world, I’d just lay out each stage carefully and then add up my costs. So that’s exactly what I’m going to do here.</p> <p><a href="//static.blog.beatthegmat.com/mba/files/2015/10/331-image-2.png"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-110933" src="//static.blog.beatthegmat.com/mba/files/2015/10/331-image-2.png" alt="331 - image 2" width="355" height="287" /></a></p> <p><strong>The correct answer is (D).</strong></p> <p>What could have been a somewhat annoying algebra problem turns into a fairly straightforward calculation. I don’t have to worry about making a mistake with setting up a formula. I just have to think carefully through what I’m actually going to have to pay for and make sure I write it all down.</p> <p>There are different ways you could set this up. I chose to figure out how much I’d have to pay for the initial typing vs. the revisions. You could also calculate for the 40 / 10 / 50 numbers that I first wrote down, but be careful with the math to avoid trap answer (A):</p> <p>40 typed = (40)(5) = 200, plus one revision = (40)(3) = 120. Total = 320</p> <p>10 typed = (10)(5) = 50, plus two revisions = (10)(6) = 60. Total = 110</p> <p>50 typed = (50)(5) = 250</p> <p>Total = 320 + 110 + 250 = 680</p> <p>What’s the trap for answer (A)? If you forget to add in the initial $5 per page for the set of 40 and the set of 10, you’ll get to answer (A), $430. Spot any other traps?</p> <p>Trap answer (C) is the result of forgetting to double the revision cost for the 10 pages that get revised twice.</p> <h2>Key Takeaways for GMAT Story Problems:</h2> <p>(1) Pretend this is happening in the real world. How would you solve? I’m confident you wouldn’t start writing equations. Do the same back-of-the-envelope calculations you’d really do if you had to figure this out for yourself.</p> <p>(2) Write all the steps down! Don’t skimp on this. Saving yourself 20 seconds by doing math in your head is a great way to make a careless mistake and lose a point that you knew how to get.</p> <p>* GMATPrep® questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.</p> <hr /> <p><em><strong><img decoding="async" loading="lazy" class="alignleft size-thumbnail wp-image-9719" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/stacey-koprince-150x150.png" alt="stacey-koprince" width="150" height="150" /><a href="https://www.manhattanprep.com/instructors/stacey-koprince/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceBioLinkGMATBlog&utm_campaign=GMAT%20Blog">Stacey Koprince</a> is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.</strong> Stacey has been teaching the GMAT, GRE, and LSAT for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests. <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=KoprinceCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/86">Check out Stacey’s upcoming GMAT courses here</a>.</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/gmat-story-problems-draw-it-out/">GMAT Story Problems: Draw It Out</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>Here’s why you might be missing GMAT Data Sufficiency problems – Part 2</title> <link>https://www.manhattanprep.com/gmat/blog/heres-why-you-might-be-missing-gmat-data-sufficiency-problems-part-1-2/</link> <dc:creator><![CDATA[Chelsey Cooley]]></dc:creator> <pubDate>Fri, 04 Dec 2015 22:18:20 +0000</pubDate> <category><![CDATA[Apps and Admissions]]></category> <category><![CDATA[Data Sufficiency]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[GMAT Resources]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[Taking the GMAT]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[Business School applications]]></category> <category><![CDATA[data sufficiency]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[gmat data sufficiency]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[how to study]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[Strategy]]></category> <category><![CDATA[study tips]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=10725</guid> <description><![CDATA[<p>Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! Check out our upcoming courses here. In our previous article, we divided the logical errors that test-takers make on Data Sufficiency questions into two types: Type 1: You thought that something was […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/heres-why-you-might-be-missing-gmat-data-sufficiency-problems-part-1-2/">Here’s why you might be missing GMAT Data Sufficiency problems – Part 2</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" loading="lazy" class="alignleft size-full wp-image-10726" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/12/blog-datasuff-part2.png" alt="Blog-DataSuff-Part2" width="676" height="264" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/12/blog-datasuff-part2.png 676w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/12/blog-datasuff-part2-300x117.png 300w" sizes="(max-width: 676px) 100vw, 676px" /></p> <p><strong><em>Did you know that you can attend the first session of any of our online or in-person GMAT courses absolutely free? We’re not kidding! <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=GMAT%20Complete%20Courses%20Plug&utm_campaign=GMAT%20Blog">Check out our upcoming courses here</a>.</em></strong></p> <hr /> <p>In <a href="https://www.manhattanprep.com/gmat/blog/2015/11/03/heres-why-you-might-be-missing-gmat-data-sufficiency-problems-part-1/">our previous article</a>, we divided the logical errors that test-takers make on Data Sufficiency questions into two types:</p> <p><strong>Type 1:</strong> You thought that something was sufficient, but it was actually insufficient.</p> <p><strong>Type 2:</strong> You thought that something was insufficient, but it was actually sufficient.</p> <p>We already covered the most common reasons for Type 1 errors to occur and a few good ways to avoid them; now, let’s cover Type 2 errors.<span id="more-10725"></span></p> <p>Type 2 errors are their opposite: also known as “false negatives,” they happen when it looks like you don’t have enough information to answer the DS question, but you actually do. The classic “(C) trap” is one example of a Type 2 error: say that you picked (C), when the right answer was actually (B). In that case, you thought that each statement was insufficient, and decided to combine them. But, it turned out that (2) was actually sufficient on its own. Oops.</p> <p>According to data from our GMAT Navigator program (in which thousands of students have recorded their answers to retired GMAT DS problems), Type 2 errors happen about 50 percent more often than</p> <p>Type 1 errors. That’s because DS problems often deliberately include statements that look useless and irrelevant, but really aren’t. If you’re not prepared, when you see one of these problems, you’ll wrongly assume that the statement is insufficient. Only well-prepared test-takers will see through the ruse.</p> <h3><strong>Here are some situations that often cause Type 2 errors:</strong></h3> <p><strong>You mistook a yes/no question for a value question.</strong> Did you see a yes/no DS question, but treat it as if you needed to solve for an exact value? Then you likely made a Type 2 error: you incorrectly assumed that because you couldn’t come up with a single value, you couldn’t answer the question. Remember that on yes/no questions, the only answers you’re looking for are ‘yes’ and ‘no’. You don’t need to come up with a specific number, and in fact, problems are often designed so that you can’t! Some yes/no questions that often lead to Type 2 errors are The Official Guide to the GMAT, 2016 (OG 2016) DS 9 and 108, and The Official Guide for GMAT Quantitative Review, 2016 (QR 2016) DS 122.</p> <p><strong>Not enough math.</strong> One rule of thumb says that in order to solve a math problem, you need at least as many equations as you have unknowns. If you’re pressed for time, use that rule on DS word problems and algebra problems. But also know that in certain special circumstances, you can solve by using fewer equations than you’d normally need. The only way to discover these special cases is to translate both the question and the statements into math on your scratch paper, and then decide whether you can solve. Otherwise, you’ll make a Type 2 error–you’ll assume that you can’t solve, when you actually can. Try these DS problems for practice: OG 2016 DS 106 and 140, and QR 2016 DS</p> <p><strong>Combo traps.</strong> Some DS value questions ask you to solve for a combination of values rather than for a single value. For instance, a DS question might ask you “What is the value of xy?” or “What percent of John’s food budget did he spend in restaurants?” In the real world, you’d solve for each individual value first (x and y, or John’s total budget and his restaurant spending). Unfortunately, the test writers design combo questions that you can actually answer without knowing the individual values, and if you fail to notice these questions, you’ll be vulnerable to Type 2 errors. That is, you might not need as much information to solve for a combination of values as you would need to solve for the values separately.</p> <p>When you review a DS value question, decide whether you were asked for one value or for a combination. If you had to find a combination of values, you may have mistakenly assumed that you needed to solve for both values separately, making a Type 2 error. To avoid this, conclusively prove each statement insufficient before you ever put them together. For some practice, try <em>OG 2016 DS</em> 52, 63, and 97.</p> <p><strong>“Nice but not necessary.”</strong> When you do a DS problem, you’re looking for the minimum amount of information that would let you answer the question correctly. That requires a different sort of thinking than solving real-world problems does.Suppose that a friend asks you to figure out the amount of water in her backyard swimming pool. She knows three things: the current depth of water in the swimming pool, how long it took her to fill it with a hose, and the rate at which her hose puts out water. You’d probably respond by asking her for all of the information she has first, and then you’d start writing equations. You might notice halfway through that you didn’t actually need to know how deep the pool was, but who cares? You’d find the answer, and your friend would walk away happy.On Data Sufficiency, you can’t ask for all of the information and then see what happens. Just because you can definitely answer the question when you use both statements together, doesn’t mean that the statements are insufficient on their own! It might be a little more complicated to answer the question using only the information from one statement, but it could still be possible.</p> <p>If you made a Type 2 error and then found yourself saying “I didn’t realize that I didn’t have to know that!” about one of the statements, then you fell for a Nice But Not Necessary trap. These questions often have a particular look to them: one statement will be very simple, usually giving you a single value, like the depth of a swimming pool or the time at which a machine began working. The other statement will be much more complex and harder to handle. Be skeptical when you see this–it might be nice to know the information from the simpler statement, but do you really need it? Or is there a more complicated solution that only uses the info from more complex statement? To practice, check out problems <em>OG 2016 DS</em> 38, 89, and 95, and <em>QR 2016 DS</em> 74 and 88.</p> <h3><strong>What now?</strong></h3> <p>With the information from this series of articles , you can categorize your Data Sufficiency errors into four types: Type 1, Type 2, Careless (simple computation mistakes and miswritings), and Mathematical (you didn’t know a rule or applied it incorrectly). Go through some DS problems you’ve done in the past and assign each wrong answer to one of those four categories. What patterns do you notice? Are your mistakes predictable?</p> <p>Then, focus specifically on your Type 2 errors. Whenever you notice one of these errors, identify the trick that you fell for. The situations described in this article often lead to Type 2 errors, but they aren’t the only possible causes. Can you come up with others? Based on the patterns you notice, make one change to how you do DS problems. Some options:</p> <ul> <li>As soon as you read a DS question, write either “value” or “yes/no” on your paper.</li> <li>Always translate DS word problems into variables and equations before deciding that a statement is insufficient.</li> <li>Before you begin solving a DS value problem, determine whether it’s a combo problem or not.</li> </ul> <p>Now that you know what these two types of logical errors look like, start trying to recognize them as you review DS problems. With time and practice, you’ll start to notice problems that would normally lead you to make Type 1 or Type 2 errors as you see them. Understanding why you made a mistake is the first step to avoiding it next time! ?</p> <hr /> <p><strong>Want full access to Chelsey’s sage GMAT wisdom? Try the first class of one of <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CooleyCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/336">her upcoming GMAT courses</a> absolutely free, no strings attached. </strong></p> <hr /> <p><em><strong><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/?utm_source=manhattanprep.com%2Fgre%2Fblog&utm_medium=blog&utm_content=CooleyBioGREBlog&utm_campaign=GRE%20Blog" target="_blank">Chelsey Cooley</a><a href="https://www.manhattanprep.com/instructors/chelsey-cooley/?utm_source=manhattanprep.com%2Fgre%2Fblog&utm_medium=blog&utm_content=CooleyBioGREBlog&utm_campaign=GRE%20Blog" target="_blank"><img decoding="async" loading="lazy" class="alignleft wp-image-10949 size-thumbnail" title="Chelsey Cooley Manhattan Prep GMAT Instructor" src="https://d27gmszdzgfpo3.cloudfront.net/gmat/wp-content/uploads/sites/18/2016/01/chelsey-cooley-150x150.png" alt="Chelsey Cooley Manhattan Prep GMAT Instructor" width="150" height="150" /></a> is a Manhattan Prep instructor based in Seattle, Washington.</strong> Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master’s degree in linguistics, a 790 on the GMAT, and a perfect 170/170 on the GRE. Check out Chelsey’s upcoming GMAT prep offerings <a href="https://www.manhattanprep.com/gmat/classes/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_medium=blog&utm_content=CooleyCoursesLinkGMATBlog&utm_campaign=GMAT%20Blog#instructor/336">here</a>.</em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/heres-why-you-might-be-missing-gmat-data-sufficiency-problems-part-1-2/">Here’s why you might be missing GMAT Data Sufficiency problems – Part 2</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>The Importance of Getting to No on the GMAT — Part 2</title> <link>https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-2/</link> <dc:creator><![CDATA[Stacey Koprince]]></dc:creator> <pubDate>Wed, 05 Aug 2015 20:31:09 +0000</pubDate> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[Fractions, Decimals, Percents]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Problem Solving]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[Taking the GMAT]]></category> <category><![CDATA[challenge problem]]></category> <category><![CDATA[fractions]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[gmat math]]></category> <category><![CDATA[GMAT prep]]></category> <category><![CDATA[gmat strategy]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[quant]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=10008</guid> <description><![CDATA[<p>Last time, we talked about how crucial it is to develop the instinct to go for the “No” when taking the GMAT. If you haven’t read the first installment, do so right now, then come back here to learn more. I left you with this GMATPrep® problem from the free exams. “*If 0</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-2/">The Importance of Getting to No on the GMAT — Part 2</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p>Last time, we talked about how crucial it is to develop the instinct to go for the “No” when taking the GMAT. If you haven’t read the first installment, <a href="//www.manhattanprep.com/gmat/blog/2015/07/30/the-importance-of-getting-to-no-on-the-gmat-part-1/">do so right now</a>, then come back here to learn more.</p> <p>I left you with this GMATPrep® problem from the free exams.</p> <blockquote><p>“*If 0 <<em>r</em>< 1 <<em>s</em>< 2, which of the following must be less than 1? “I. <img decoding="async" class="" title="r/s" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_985_61fc9c9aee68e5368c0329f9b901e29e.png" alt="r/s" /></p> <p>“II. <em>rs</em></p> <p>“III. <em>s</em> – <em>r</em></p> <p>“(A) I only</p> <p>“(B) II only</p> <p>“(C) III only</p> <p>“(D) I and II</p> <p>“(E) I and III”</p></blockquote> <p>Let’s talk about it now!</p> <p><span id="more-10008"></span></p> <p><img decoding="async" loading="lazy" class=" size-medium wp-image-10010 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/08/315-image-1-300x241.png" alt="315 - image 1" width="300" height="241" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/08/315-image-1-300x241.png 300w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/08/315-image-1.png 351w" sizes="(max-width: 300px) 100vw, 300px" /></p> <p>What did you think when you first <em>Glanced</em> at this thing? I thought, “Ugh, roman numerals.” These questions annoy me because they often take longer to do. In fact, unless I can spot some kind of shortcut, I may bail and move on. I’m not interested in doing the work of 3 problems for the price of 1!</p> <p>When I <em>Read</em> this one, though, I realized it wasn’t too terrible. I <em>Jotted</em> this down while I read:</p> <p style="text-align: center;">0 <<em>r</em>< 1 <<em>s</em>< 2 MUST be < 1?</p> <p>And then I <em>Reflected</em>. First, I glanced at the statements and saw that they all contain both <em>r</em> and <em>s</em>. I also glanced down at the answers and thought, “Hmm, I bet roman numeral I works; it’s in three of the answer choices.”</p> <p>Then, I looked back at the stuff I jotted down and thought about what it tells me. The value of <em>r</em> is between 0 and 1; it’s a fraction. The value of <em>s</em> is between 1 and 2. All right, that’s also technically a fraction or decimal, but it’s a very different category than <em>r</em>, which is a fraction between 0 and 1. Fractions between 0 and 1 can do funny things to certain math operations.</p> <p>They want to know what <em>must</em> be less than 1, so that would either be another fraction between 0 and 1, the number 0, or something negative.</p> <p>I think I’ve got my thoughts all <em>Organized</em>. Time to <em>Work</em> on this thing!</p> <blockquote><p>“I. <img decoding="async" title="r/s" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_985_61fc9c9aee68e5368c0329f9b901e29e.png" alt="r/s" />“</p></blockquote> <p>Time to test cases. What if <em>r</em> = <img decoding="async" title="1/2" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_984_7827c38498fd06c395fac2a30b119c50.png" alt="1/2" /> and <em>s</em> = <img decoding="async" title="3/2" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_984_ae036e0f8b5e6c304222eef2dfdafdad.png" alt="3/2" />? Then:</p> <p><img decoding="async" title="r/s={1/2}/{3/2}={1/2}*{2/3}=1/3" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_967_95fa5d790fe726b092e89c9fd090e9e3.png" alt="r/s={1/2}/{3/2}={1/2}*{2/3}=1/3" /></p> <p>Yes, that’s less than 1. Can I get a no? In order to do that, I’d have to get 1 or something greater than 1.</p> <p>I can’t get 1 because <em>r</em> and <em>s</em> don’t equal each other. What about something greater than 1?</p> <p>Think it through. Turns out, that’s impossible! The numerator is the starting point. It’s between 0 and 1. Then, divide by the denominator. That’s greater than 1. Dividing by a number greater than 1 will always have the effect of making the numerator smaller. If the numerator is already smaller than 1, then the final number can’t be larger than 1.</p> <p>Done! The first roman numeral must be less than 1. Eliminate answers (B) and (C). (Note: if you had to guess on this one, guess that it works, since roman numeral I appears in three of the five answer choices.)</p> <p>In fact, glancing at those answers before you start to solve may help you to manage your time. You might be annoyed by the amount of work necessary to solve this one and decide that you’ll only try roman numeral I, since it shows up in three of the answers. Then, when you’ve eliminated either two or three of the answers after evaluating just one statement, you might guess and move on.</p> <blockquote> <p style="text-align: left;">“II. <em>rs</em>”</p> </blockquote> <p>Test cases again! Remember that <em>r</em> still has to be between 0 and 1 and <em>s</em> still has to be between 1 and 2.</p> <p>Case 1: <em>r</em> = 1/2 and <em>s</em> = 3/2. The product is 3/4, which is less than 1.</p> <p>Can you find a no? Try before you keep reading.</p> <p>In this case, a variation on testing cases might be valuable: test extremes. The upper limit for<em> r</em> is something just a little bit less than 1. Likewise, the upper limit for<em>s</em> is something just a little bit less than 2. What would happen if <em>r</em> and <em>s</em> actually equaled 1 and 2, respectively?</p> <p>Then, the product would be 2. So the product of a number just a little bit less than 1 and another number just a little bit less than 2 should be a little less than 2—but greater than 1. This statement, then, does not have to be less than 1.</p> <p>You can also test numbers to prove this. Make both numbers as big as you can while still making the math not-too-terrible to do. If <em>s</em> = 1.8 and <em>r</em> = 0.9, then think of the math as taking 90% of 1.8. That’s greater than 1, even if you don’t do the exact math to figure out what that product is. <img src="https://s.w.org/images/core/emoji/14.0.0/72x72/1f642.png" alt="🙂" class="wp-smiley" style="height: 1em; max-height: 1em;" /></p> <p>Eliminate answer (D).</p> <blockquote><p>“III. <em>s</em> – <em>r</em>”</p></blockquote> <p>Last one! Okay, remind yourself again: <em>s</em> is between 1 and 2 and <em>r</em> is between 0 and 1. (Careful. Note that the order of the variables is reversed now.)</p> <p>Case 1: If <em>s</em> = 3/2 and <em>r </em>= 1/2, then the difference is 1. Hey, for the first time, the first case is <em>not</em> less than 1! This statement also doesn’t qualify, so eliminate answer (E).</p> <p>The correct answer is (A).</p> <h2>Key Takeaways for Getting to No:</h2> <p>(1) You can use the Getting to No technique on some problem solving (PS) questions, too, not just data sufficiency. When you see PS questions that ask what must or could be true (or cannot be true), don’t just go for the Yes! Think about how to Get to No. (Remember the Skeptical Scientist takeaway from part 1 of this series).</p> <p>(2) If you are actively trying to Get to No but can’t, then the chances are pretty good that this statement actually <em>must</em> be less than 1 (or whatever the problem asks you to find). In your quest to find that No, you may even be able to prove why you can’t get there, as we did for roman numeral I in the problem above.</p> <p><em>* GMATPrep® questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.</em></p> <hr /> <p> </p> <p> </p> <p><em><strong><img decoding="async" loading="lazy" class=" wp-image-9719 size-thumbnail alignleft" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/stacey-koprince-150x150.png" alt="stacey-koprince" width="150" height="150" />Stacey Koprince is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.</strong> Stacey has been teaching the GMAT, GRE, and LSAT for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests. <a href="//www.manhattanprep.com/gmat/classes/#instructor/86">Check out Stacey’s upcoming GMAT courses here</a></em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-2/">The Importance of Getting to No on the GMAT — Part 2</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>The Importance of Getting to No on the GMAT — Part 1</title> <link>https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-1/</link> <dc:creator><![CDATA[Stacey Koprince]]></dc:creator> <pubDate>Thu, 30 Jul 2015 01:27:59 +0000</pubDate> <category><![CDATA[Data Sufficiency]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[data sufficiency]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[gmat strategy]]></category> <category><![CDATA[gmat studies]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[study tips]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=9878</guid> <description><![CDATA[<p>Recently, a colleague of mine shared this very interesting puzzle published by the New York Times. (Thanks, Ceilidh!) Go ahead and try it. I’ll wait. After you’ve tried the puzzle, you can read the short article that goes with it. What did you learn about how humans tend to think? More important, what did you […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-1/">The Importance of Getting to No on the GMAT — Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" loading="lazy" class="alignleft wp-image-9882 size-medium" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/social-no-pt1-300x300.png" alt="Social-No-Pt1" width="300" height="300" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/social-no-pt1-300x300.png 300w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/social-no-pt1-150x150.png 150w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/social-no-pt1.png 504w" sizes="(max-width: 300px) 100vw, 300px" />Recently, a colleague of mine <a href="//www.nytimes.com/interactive/2015/07/03/upshot/a-quick-puzzle-to-test-your-problem-solving.html">shared this very interesting puzzle published by the New York Times</a>. (Thanks, Ceilidh!)</p> <p>Go ahead and try it. I’ll wait. After you’ve tried the puzzle, you can read the short article that goes with it.</p> <p>What did you learn about how humans tend to think? More important, what did you learn about how <em>you</em> think?</p> <p>That tendency to look for the <em>no</em>, or to try to disprove something, is a trait shared by <a href="https://en.wikipedia.org/wiki/Scientific_method">scientists</a>, <a href="//www.merriam-webster.com/dictionary/devil%27s%20advocate">devil’s advocates</a>, and <a href="https://www.manhattanprep.com/gmat/instructors/">great standardized test takers</a>. You can learn to make this your natural reaction, too!</p> <p><span id="more-9878"></span>Try this Data Sufficiency (DS) problem from the free GMATPrep® exams. (Note: if you have not yet taken your two free GMATPrep exams, you may want to wait until you’ve done so before you read further. Also, if you have not yet studied DS enough to know what the five answer choices are, bookmark this article and come back to it after you have memorized the DS answer choices.)</p> <p style="padding-left: 30px;">“*Is<em> x</em> less than 20?</p> <p style="padding-left: 30px;">“(1) The sum of <em>x</em> and <em>y</em> is less than 20.</p> <p style="padding-left: 30px;">“(2) <em>y</em> is less than 20″</p> <p>Ready?</p> <p>Here’s our framework for working through a GMAT problem:</p> <p><img decoding="async" loading="lazy" class="aligncenter wp-image-9840 size-medium" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/306-image-1-300x241.png" alt="306 - image 1" width="300" height="241" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/306-image-1-300x241.png 300w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/306-image-1.png 351w" sizes="(max-width: 300px) 100vw, 300px" /></p> <p><em>Glance</em>: It’s a DS problem. Words—I’ll have to do a little translating. Doesn’t seem to be a big story, though.</p> <p><em>Read</em>: It’s a yes/no question, so I don’t necessarily have to find the exact value of <em>x</em>.</p> <p><em>Jot</em>:</p> <p style="text-align: center;">Is<em> x</em> < 20?</p> <p><em>Reflect</em>: They haven’t actually told me anything about <em>x</em>. The value could be anything: negative, 0, a fraction.</p> <p><em>Jot</em> some more and <em>Organize</em>. The two statements are pretty easy, so I chose to translate both at once, before starting to work on them:</p> <p><img decoding="async" loading="lazy" class="aligncenter wp-image-9879 size-full" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2120-image-1.png" alt="2015-07-29_2120_image_1" width="541" height="211" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2120-image-1.png 541w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2120-image-1-300x117.png 300w" sizes="(max-width: 541px) 100vw, 541px" /></p> <p>Note: Although statement (2) is arguably easier, statement (1) isn’t really hard. My default is to start with statement (1) unless it looks ugly or annoying, so I’m starting with statement (1).</p> <p><em>Reflect</em> again, then <em>Work</em>. What should I do with statement (1)? I can test cases:</p> <p><img decoding="async" loading="lazy" class="aligncenter wp-image-9880 size-full" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2121-image-2.png" alt="2015-07-29_2121_image_2" width="282" height="236" /></p> <p>Look what I did there. The first case that I tested did give me a Yes answer. But then I didn’t just pick any random number to try for my second case. I thought, “Hey, what could give me the opposite answer? I want to find a No, if possible!”</p> <p>(By the way, that “val?” column is short for “valid?” It’s crucial to make sure that you choose numbers that make the statement valid. Otherwise, discard that case!)</p> <p>Okay, so statement (1) is not sufficient (NS); eliminate answers (A) and (D). What about statement (2)? It doesn’t even mention <em>x</em>, so it’s not sufficient either. Eliminate answer (B). Put the two statements together.</p> <p><img decoding="async" loading="lazy" class="aligncenter wp-image-9881 size-full" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2121-image-3.png" alt="2015-07-29_2121_image_3" width="549" height="442" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2121-image-3.png 549w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/07/2015-07-29-2121-image-3-300x242.png 300w" sizes="(max-width: 549px) 100vw, 549px" /></p> <p>Check it out! The first two cases for statement (1) still work even when you add statement (2) to the mix. Even together, the two statements are not sufficient to answer the question.</p> <p>The correct answer is (E).</p> <p>Try this one (also from GMATPrep) and we’ll talk about it next time:</p> <p style="padding-left: 30px;">“*If 0 < <em>r</em> < 1 < <em>s</em> < 2, which of the following must be less than 1?</p> <p style="padding-left: 30px;">“I. <img decoding="async" title="r/s" src="//www.beatthegmat.com/mba/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_985_61fc9c9aee68e5368c0329f9b901e29e.png" alt="r/s" /></p> <p style="padding-left: 30px;">“II. <em>rs</em></p> <p style="padding-left: 30px;">“III. <em>s</em> – <em>r</em></p> <p style="padding-left: 30px;">“(A) I only</p> <p style="padding-left: 30px;">“(B) II only</p> <p style="padding-left: 30px;">“(C) III only</p> <p style="padding-left: 30px;">“(D) I and II</p> <p style="padding-left: 30px;">“(E) I and III”</p> <h4>Key Takeaways for Getting to No:</h4> <p>(1) Your job is to be a skeptical scientist. What better way to confirm your theory than to try to disprove it as rigorously as you can? If you can find a valid case that gives a No answer, as well as a case that gives a Yes answer, then you’re done: this statement is not sufficient to answer the question.</p> <p>(2) If you are actively trying to disprove and you can’t, then the chances are pretty good that this statement is actually sufficient. Yes, it might be the case that you have just not found the right number to test yet. But if you are actively trying to disprove, then your brain will be thinking about the “weird” numbers that might make a difference—so you can feel pretty confident that you’ve probably got it.</p> <p><em>* GMATPrep® questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.</em></p> <hr /> <p><em><strong><img decoding="async" loading="lazy" class="alignleft wp-image-9719 size-thumbnail" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/stacey-koprince-150x150.png" alt="stacey-koprince" width="150" height="150" />Stacey Koprince is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.</strong> Stacey has been teaching the GMAT, GRE, and LSAT for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests. <a href="//www.manhattanprep.com/gmat/classes/#instructor/86">Check out Stacey’s upcoming GMAT courses here!</a></em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/the-importance-of-getting-to-no-on-the-gmat-part-1/">The Importance of Getting to No on the GMAT — Part 1</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>Everything you need to know about the New Official Guides, Part 3</title> <link>https://www.manhattanprep.com/gmat/blog/everything-you-need-to-know-about-the-new-official-guides-part-3/</link> <dc:creator><![CDATA[Stacey Koprince]]></dc:creator> <pubDate>Wed, 17 Jun 2015 23:20:13 +0000</pubDate> <category><![CDATA[Data Sufficiency]]></category> <category><![CDATA[GMAC]]></category> <category><![CDATA[GMAT Announcements]]></category> <category><![CDATA[News]]></category> <category><![CDATA[Problem Solving]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[2016 Official Guides]]></category> <category><![CDATA[data sufficiency]]></category> <category><![CDATA[problem solving]]></category> <category><![CDATA[quant]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=9679</guid> <description><![CDATA[<p>I have now done every last one of the new quant problems in both new books—and there are some really neat ones! I’ve also got some interesting observations for you. (If you haven’t yet read my earlier installments, start here.) In this installment, I’ll discuss my overall conclusions for quant and I’ll also give you […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/everything-you-need-to-know-about-the-new-official-guides-part-3/">Everything you need to know about the New Official Guides, Part 3</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p>I have now done every last one of the new quant problems in both new books—and there are some really neat ones! I’ve also got some interesting observations for you. (If you haven’t yet read my earlier installments, <a href="https://www.manhattanprep.com/gmat/blog/2015/06/08/everything-you-need-to-know-about-the-new-official-guides-part-1/">start here</a>.)</p> <p>In this installment, I’ll discuss my overall conclusions for quant and I’ll also give you all of the problem numbers for the new problems in both the big OG and the smaller quant-only OG.</p> <h2>What’s new in Quant?</h2> <p>Now that I’ve seen everything, I’ve been able to spot some trends across all of the added and dropped questions. For example, across both The Official Guide for GMAT® Review (aka the big book) and The Official Guide for GMAT® Quant Review (aka quant-only or the quant supplement), Linear Equation problems dropped by a count of 13. This is the differential: new questions minus dropped questions.</p> <p>That’s a pretty big number; the next closest categories, Inequalities and Rates & Work, dropped by 5 questions each. I’m not convinced that a drop of 5 is at all significant, but I decided that was a safe place to stop the “Hmm, that’s interesting!” count.</p> <p>Now, a caveat: there are sometimes judgment calls to make in classifying problems. Certain problems cross multiple content areas, so we do our best to pick the topic area that is most essential in solving that problem. But that 13 still stands out. <img src="https://s.w.org/images/core/emoji/14.0.0/72x72/1f642.png" alt="🙂" class="wp-smiley" style="height: 1em; max-height: 1em;" /></p> <p>The biggest jump came from Formulas, with 10 added questions across both sources. This category includes sequences and functions; just straight translation or linear equations would go into those respective categories, not formulas. Positive & Negative questions jumped by 7, weighted average jumped by 6, and coordinate plane jumped by 5.</p> <p>Given that Linear Equations dropped and Formulas jumped, could it be the case that they are going after somewhat more complex algebra now? That’s certainly possible. I didn’t feel as though the new formula questions were super hard though. It felt more as though they were testing whether you could <em>follow directions</em>. If I give you a weird formula with specific definitions and instructions, can you interpret correctly and manipulate accordingly?</p> <p>If you think about it, work is a lot more like this than “Oh, here are two linear equations; can you solve for <em>x</em>?” So it makes sense that they would want to emphasize questions of a more practical nature.</p> <p><span id="more-9679"></span></p> <h2>Anything interesting about the new questions?</h2> <p>In an earlier installment, I told you about some interesting problems from the big book. Here are a few more observations from the Quant-only supplemental book.</p> <p><em>Problem Solving</em><br /> Of the 176 questions in the Problem Solving (PS) section, 44 of them are new. (Disclaimer: I hope I counted correctly for all of these sections, but I’ve been going through about 1,500 questions and hundreds of pages quickly in order to get this review out to you right away. So please forgive me if I miscounted anything! I’ll correct any errors as soon as I find out about them.)</p> <p><em>Note: I can’t actually reproduce the text of the question for copyright reasons, but I’ll cite the problem number so that you can look it up if you do decide to buy the book.</em></p> <p>A number of questions relied on some type of pattern recognition: #125, #143, #161. They’re not interested in you doing crazy math. They’re interested in whether you can recognize patterns and draw some kind of meaningful conclusion.</p> <p>In my notes, I labeled #80 “Wow. That’s just mean.” And #152 got a “Pure evil” tag. (#152 requires mental manipulation of a 3-D shape and that’s just not something I have ever been able to do.)</p> <p>I’d far rather work backwards on #127 than do the actual math. Others may feel differently, but the textbook math on this one is pretty annoying.</p> <p><em>Data Sufficiency</em><br /> Of the 124 Data Sufficiency (DS) problems, 32 are new to this edition of the Quant OG. There were some doozies.</p> <p>I couldn’t believe #124, the highest numbered question in the section: a parabola inequality (not even an equation!). Now, if you like geometry, great—learn how to tackle parabolas. If you don’t, then if you happen to get one of these on the real test, give yourself a mental high five for earning this question, then pick your favorite letter and move on!</p> <p>I almost fell into the trap on #123. I’m so used to rate and work questions specifying that <em>whatever</em> was moving at a steady rate that I almost didn’t notice the omission in this one…</p> <p>Also, as with the big book, I was <a href="https://www.manhattanprep.com/gmat/blog/2015/03/19/gmat-problem-solving-strategy-test-cases/">testing cases</a> all the time on these DS problems. That technique is just a lifesaver (and it even works on some PS problems!).</p> <h2>So what are all the NEW problem numbers?</h2> <p>Here you go! I’ve got these organized by book and question type.</p> <p><em><span style="text-decoration: underline;">The Official Guide for GMAT®</span></em><em><span style="text-decoration: underline;"> Review 2016 (aka the big OG)</span></em></p> <p style="text-align: left;"><em>Problem Solving<br /> Key: FDP = Fractions, Decimals, & Percents; WP = Word Problems; NP = Number Properties</em></p> <p><img decoding="async" loading="lazy" class=" wp-image-9686 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-1-753x1024.png" alt="OG 2016 PS #1" width="500" height="680" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-1-753x1024.png 753w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-1-221x300.png 221w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-1.png 874w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p><img decoding="async" loading="lazy" class="aligncenter wp-image-9687" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-2.png" alt="OG 2016 PS #2" width="500" height="572" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-2.png 870w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ps-2-262x300.png 262w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p> </p> <p><em>Data Sufficiency<br /> Key: FDP = Fractions, Decimals, & Percents; WP = Word Problems; NP = Number Properties</em></p> <p><img decoding="async" loading="lazy" class=" wp-image-9684 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-1.png" alt="OG 2016 DS #1" width="500" height="455" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-1.png 866w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-1-300x273.png 300w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p><img decoding="async" loading="lazy" class=" wp-image-9685 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-2.png" alt="OG 2016 DS #2" width="500" height="435" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-2.png 866w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/og-2016-ds-2-300x261.png 300w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p> </p> <p><em><span style="text-decoration: underline;">The Official Guide for GMAT<em><span style="text-decoration: underline;">®</span></em></span></em><em><span style="text-decoration: underline;"> Quant Review 2016 (aka the quant-only book)</span></em></p> <p><em>Problem Solving<br /> Key: FDP = Fractions, Decimals, & Percents; WP = Word Problems; NP = Number Properties</em></p> <p><img decoding="async" loading="lazy" class=" wp-image-9694 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps1.png" alt="Q 2016 PS#1" width="500" height="550" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps1.png 866w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps1-273x300.png 273w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p><img decoding="async" loading="lazy" class=" wp-image-9693 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps-2.png" alt="Q 2016 PS #2" width="500" height="386" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps-2.png 870w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ps-2-300x232.png 300w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p> </p> <p><em>Data Sufficiency<br /> Key: FDP = Fractions, Decimals, & Percents; WP = Word Problems; NP = Number Properties</em></p> <p><img decoding="async" loading="lazy" class=" wp-image-9691 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-1.png" alt="Q 2016 DS #1" width="500" height="271" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-1.png 866w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-1-300x163.png 300w" sizes="(max-width: 500px) 100vw, 500px" /></p> <p><img decoding="async" loading="lazy" class=" wp-image-9692 aligncenter" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-2.png" alt="Q 2016 DS #2" width="500" height="403" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-2.png 866w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/06/q-2016-ds-2-300x242.png 300w" sizes="(max-width: 500px) 100vw, 500px" /></p> <h2>What about Verbal?</h2> <p>Next time, we’ll dive into the final summary of everything verbal and I’ll also have the problem lists for you.</p> <p>Until then, happy studying!</p> <p> </p> <p><a href="//www.manhattanprep.com/gmat/blog/2015/06/19/everything-you-need-to-know-about-the-new-official-guides-part-4/"><strong>Check out Part 4 of this series</strong></a></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/everything-you-need-to-know-about-the-new-official-guides-part-3/">Everything you need to know about the New Official Guides, Part 3</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> <item> <title>When Your High School Algebra is Wrong: How the GMAT Breaks Systems of Equations Rules</title> <link>https://www.manhattanprep.com/gmat/blog/high-school-algebra-wrong-gmat-breaks-systems-equations-rules/</link> <dc:creator><![CDATA[Céilidh Erickson]]></dc:creator> <pubDate>Thu, 19 Feb 2015 16:54:08 +0000</pubDate> <category><![CDATA[Algebra]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[algebra]]></category> <category><![CDATA[algebra tips]]></category> <category><![CDATA[b-school]]></category> <category><![CDATA[business school]]></category> <category><![CDATA[equations]]></category> <category><![CDATA[GMAT]]></category> <category><![CDATA[gmat quant]]></category> <category><![CDATA[gmat strategy]]></category> <category><![CDATA[Graduate Management Admission Test]]></category> <category><![CDATA[Manhattan GMAT]]></category> <category><![CDATA[MBA]]></category> <category><![CDATA[quant]]></category> <category><![CDATA[study tips]]></category> <category><![CDATA[Tips]]></category> <guid isPermaLink="false">http://www.manhattanprep.com/gmat/?p=8472</guid> <description><![CDATA[<p>If you have two equations, you can solve for two variables. This rule is a cornerstone of algebra. It’s how we solve for values when we’re given a relationship between two unknowns: If I can buy 2 kumquats and 3 rutabagas for $16, and 3 kumquats and 1 rutabaga for $9, how much does 1 […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/high-school-algebra-wrong-gmat-breaks-systems-equations-rules/">When Your High School Algebra is Wrong: How the GMAT Breaks Systems of Equations Rules</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><strong><em><img decoding="async" loading="lazy" class="alignleft wp-image-8487" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2015/02/2-17-highschool-2.png" alt="2-17-HighSchool-2" width="375" height="375" />If you have two equations, you can solve for two variables.</em></strong></p> <p>This rule is a cornerstone of algebra. It’s how we solve for values when we’re given a relationship between two unknowns:</p> <p style="padding-left: 30px"><em>If I can buy 2 kumquats and 3 rutabagas for $16, and 3 kumquats and 1 rutabaga for $9, how much does 1 kumquat cost?</em></p> <p>We set up two equations:</p> <p style="padding-left: 30px">2k + 4r = 16</p> <p style="padding-left: 30px">3k + r = 9</p> <p>Then we can use either substitution or elimination to solve. (Try it out yourself; answer* below).</p> <p>On the GMAT, you’ll be using the “2 equations à 2 variables” rule to solve for a lot of word problems like the one above, especially in Problem Solving. Be careful, though! On the GMAT this rule doesn’t <em>always</em> apply, especially in Data Sufficiency. Here are some sneaky exceptions to the rule…</p> <p><strong>2 Equations aren’t always 2 equations</strong><br /> <span id="more-9238"></span></p> <p>On DS questions, the GMAT wants you to <em>assume</em> that if you have 2 equations, you can always solve for the values of 2 variables. Consider:</p> <p style="padding-left: 30px">What is the value of <em>x</em>?</p> <p style="padding-left: 30px"> (1) 2<em>x</em> – <em>y</em> = 5<em>x</em> – 4</p> <p style="padding-left: 30px"> (2) 6<em>x</em> + <em>y</em> = 8 – <em>y</em></p> <p>At a first glance, we see that each statement has an equation with <em>x</em> and <em>y</em> in it. We assume that those aren’t sufficient on their own, but if we combine them, then 2 equations should allow us to solve for 2 variables. Right? Give it a try – see what values you get…</p> <p>If you actually try to solve, you’ll see that statement (1) simplifies to 3<em>x</em> + <em>y</em> = 4. And statements (2) simplifies to… exactly the same thing! We didn’t really have 2 equations – we actually had 2 versions of the <em>same</em> equation. The answer would be E, not C.</p> <p><strong>2 variables aren’t always 2 variables</strong></p> <p>Try this one:</p> <p style="padding-left: 30px">What is the value of <em>m</em>?</p> <p style="padding-left: 30px"> (1) <em>m</em> – 2<em>n</em> = 6</p> <p style="padding-left: 30px"> (2) 3<em>m</em> – <em>n</em> = 9 – (<em>m</em> + <em>n</em>)</p> <p>Again, at a first glance it looks like each equation has 2 variables, so we’ll need both statements to solve. What happens when you simplify statement (2), though? The –<em>n</em> on each side will cancel, leaving us with a value for <em>m</em>. That’s sufficient!</p> <p>We have to actually do the work to ensure that a) neither variable cancels out or b) we don’t secretly have the same equation. We can’t just jump to a conclusion without doing the work!</p> <p><strong>The “Combo”</strong></p> <p style="padding-left: 30px">If <em>p</em> + 3<em>q</em> = 6<em>r</em>, what is the value of <em>p</em>?</p> <p style="padding-left: 30px"> (1) 2<em>r</em> – <em>q</em> = 5</p> <p style="padding-left: 30px"> (2) <em>r</em> + 2<em>q</em> = 20</p> <p>Here, if we combine the two statements, we can solve and find that <em>q</em> = 7 and <em>r</em> = 6, and then we can easily solve for the value of <em>p</em>. So it seems like the answer should be C, right? But of course the GMAT is sneakier than that…</p> <p>Sometimes 2 equations will let us solve for the values of 2 variables, but <em>that’s not what the question really asked</em>! First, rephrase the question:</p> <p style="padding-left: 30px">If <em>p</em> + 3<em>q</em> = 6<em>r</em>, what is the value of <em>p</em>?</p> <p style="padding-left: 30px"> <em>p</em> = 6<em>r</em> – 3<em>q</em> → what is the value of 6<em>r</em> – 3<em>q</em>?</p> <p style="padding-left: 30px"> → what is 3(2<em>r</em> – <em>q</em>)?</p> <p style="padding-left: 30px"> → what is 2<em>r</em> – <em>q</em>?</p> <p>If that’s our question, then clearly statement (1) gives us a value for that expression. We didn’t need the value of each variable individually, we just needed a value for the “combo” of 2<em>r</em> – <em>q</em>.</p> <p><strong>The Integer Constraint</strong></p> <p>If I asked you to solve for <em>x</em>, and just gave you the equation 13<em>x</em> + 5<em>y</em> = 90, you wouldn’t be able to do it. One equation will never let you solve for two variables – that’s what we learned in high school. But see what happens when we have a word problem:</p> <p style="padding-left: 30px">If xylophones cost $13 apiece and…. [I can’t think of an instrument that starts with ‘y.’ Let’s just say ‘zithers’] zithers cost $5 apiece at the Discount Music Emporium. If Wolfgang purchased at least one xylophone and one zither, then how many xylophones did Wolfgang buy?</p> <p style="padding-left: 30px"> (1) He spent a total of $90 on xylophones and zithers.</p> <p style="padding-left: 30px"> (2) He bought the same number of xylophones as zithers.</p> <p>If we use both statements together, we get 13<em>x</em> + 5<em>z</em> = 90 and <em>x</em> = <em>z</em>. Two equations, so we can solve for two variables. But look again at the statements individually!</p> <p>The second statement doesn’t help, because that “same number” could be anything. On the first statement, though, ask yourself: are there multiple combinations of $13 and $5 amounts that could add to $90?</p> <p>Because the numbers of xylophones and zithers have to be <em>positive integers</em>, we’re just looking for combinations of multiples of 13 and multiples of 5. As it turns out, there’s only one combination that adds up to $90: 13(5) + 5(5). Statement (1) – just one single equation! – was sufficient because the integer constraint restricted it to one possibility.</p> <p><strong>The Quadratic</strong></p> <p>Another way that the GMAT will try to mess with our expectations about “2 equations → 2 variables” is by giving us two equations that create a quadratic:</p> <p style="padding-left: 30px">What is the value of <em>k</em>?</p> <p style="padding-left: 30px"> (1) <em>j</em> + <em>k</em> = 9</p> <p style="padding-left: 30px"> (2) <em>jk</em> = 20</p> <p>If we combine these two equations, we’ll get a quadratic:</p> <p style="padding-left: 30px">20/<em>k</em> + <em>k</em> = 9</p> <p style="padding-left: 30px">20 + <em>k</em><sup>2</sup> -9<em>k</em> = 0</p> <p style="padding-left: 30px">(<em>k</em> – 5)(<em>k</em> – 4) = 0</p> <p>We find that <em>k </em>could equal 4 or 5, but we’ll never know which. Quadratics give us two potential values, but they’re insufficient to give us a single value for a variable (unless there’s a constraint, or a perfect square). Here, the answer would be E.</p> <p><strong>Check your assumptions!</strong></p> <p>Remember, the GMAT likes to thwart your expectations! Don’t assume that two equations will always be needed (or sufficient) to solve for two variables.</p> <p>For more examples of these “2 equations ≠ 2 variables,” try these problems. See if you can pinpoint which exception is being used in each:</p> <p>OG 13/2015: DS #17, 23, 56, 59, 67, 68, 78, 114, 132, 156</p> <p>* <em>k</em> = 2</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/high-school-algebra-wrong-gmat-breaks-systems-equations-rules/">When Your High School Algebra is Wrong: How the GMAT Breaks Systems of Equations Rules</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> </channel> </rss>