<?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>GMAT Masks – GMAT</title> <atom:link href="https://www.manhattanprep.com/gmat/blog/tag/gmat-masks/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, 30 Aug 2019 17:35:38 +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 GMAT’s G-MASKs</title> <link>https://www.manhattanprep.com/gmat/blog/gmat-masks/</link> <dc:creator><![CDATA[Reed Arnold]]></dc:creator> <pubDate>Fri, 27 Jul 2018 16:50:35 +0000</pubDate> <category><![CDATA[Algebra]]></category> <category><![CDATA[For Current Studiers]]></category> <category><![CDATA[GMAT Prep]]></category> <category><![CDATA[GMAT Resources]]></category> <category><![CDATA[GMAT Strategies]]></category> <category><![CDATA[GMAT Study Guide]]></category> <category><![CDATA[How to Study]]></category> <category><![CDATA[Quant]]></category> <category><![CDATA[Verbal]]></category> <category><![CDATA[Exponents]]></category> <category><![CDATA[GMAT Masks]]></category> <guid isPermaLink="false">https://www.manhattanprep.com/gmat/?p=16052</guid> <description><![CDATA[<p>You can and should murder me for that pun. But first, a question. What is a simplified way of writing 3x + 3x + 3x? Tough question. You might not have seen something like that before. How are you supposed to know what to do? Easier question. What is a nice, simplified way of writing […]</p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/gmat-masks/">The GMAT’s G-MASKs</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></description> <content:encoded><![CDATA[<p><img decoding="async" fetchpriority="high" class="alignnone size-full wp-image-16084" src="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2018/07/gmat-g-masks-reed-arnold.png" alt="Manhattan Prep GMAT Blog - The GMAT's G-MASKs by Reed Arnold" width="1200" height="628" srcset="https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2018/07/gmat-g-masks-reed-arnold.png 1200w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2018/07/gmat-g-masks-reed-arnold-300x157.png 300w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2018/07/gmat-g-masks-reed-arnold-768x402.png 768w, https://cdn2.manhattanprep.com/gmat/wp-content/uploads/sites/18/2018/07/gmat-g-masks-reed-arnold-1024x536.png 1024w" sizes="(max-width: 1200px) 100vw, 1200px" /></p> <p><span style="font-weight: 400;"><iframe src="https://giphy.com/embed/l3q2K5jinAlChoCLS" width="409" height="480" frameBorder="0" class="giphy-embed" allowFullScreen></iframe></p> <p><a href="https://giphy.com/gifs/mashable-l3q2K5jinAlChoCLS"></a></p> <p></span></p> <p><span style="font-weight: 400;">You can and should murder me for that pun.</span><span id="more-16052"></span></p> <p><span style="font-weight: 400;">But first, a question. What is a simplified way of writing 3</span><span style="font-weight: 400;"><sup>x</sup> </span><span style="font-weight: 400;">+ 3</span><span style="font-weight: 400;"><sup>x</sup> </span><span style="font-weight: 400;">+ 3</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;">?</span></p> <p><span style="font-weight: 400;">Tough question. You might not have seen something like that before. How are you supposed to know what to do?</span></p> <p><span style="font-weight: 400;">Easier question. What is a nice, simplified way of writing x + x + x?</span></p> <p><span style="font-weight: 400;">You probably got this one easily. x + x + x is just 3x.</span></p> <p><span style="font-weight: 400;">Not even an issue, right? But what’s the difference between these two things, really? If I add three of the same number, the outcome should always be three times that number. 2 + 2 + 2 is 3(2) = 6. x + x + x = 3x.</span></p> <p><span style="font-weight: 400;">So 3</span><span style="font-weight: 400;"><sup>x</sup> </span><span style="font-weight: 400;">+ 3</span><span style="font-weight: 400;"><sup>x</sup> </span><span style="font-weight: 400;">+ 3</span><span style="font-weight: 400;"><sup>x</sup> </span><span style="font-weight: 400;">= 3(3</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;">), which, using my exponent rules, equals 3</span><span style="font-weight: 400;"><sup>x+1</sup> </span><span style="font-weight: 400;">(because 3(3</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;">) can be written as</span> <span style="font-weight: 400;">3</span><span style="font-weight: 400;"><sup>1</sup></span><span style="font-weight: 400;">(3</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;">)).</span></p> <p><span style="font-weight: 400;">This is an example of one of the GMAT’s favorite moves: making you think you don’t know how to do something because they’ve put something that looks weird onto a process that you know how to do.</span></p> <p><span style="font-weight: 400;">I call these ‘GMAT masks.’ They’re disguises, nothing more. They are Batman’s cowl and Clark Kent’s glasses, except instead of hiding superheroes, they hide, y’know… math and stuff. They’re designed to blind you to rules you know and processes you can do.</span></p> <p><span style="font-weight: 400;">Here’s another example I use in my classes.</span></p> <p><span style="font-weight: 400;">Put a minute on the clock and try to simplify the following:</span></p> <p><span style="font-weight: 400;"> (x-y)/(√x + √y)</span></p> <p><span style="font-weight: 400;">Maybe you were able to do this, in which case you </span><i><span style="font-weight: 400;">probably</span></i><span style="font-weight: 400;"> were able to see through the GMAT’s disguise. But most students struggle to get through that.</span></p> <p><span style="font-weight: 400;">Try another. Give yourself a minute to simplify:</span></p> <p><span style="font-weight: 400;">(x²</span><span style="font-weight: 400;"> – y²</span><span style="font-weight: 400;">)/(x+y)</span></p> <p><span style="font-weight: 400;">How’d you do? A lot of people get this one in about 15 seconds (if you haven’t, brush up on your common quadratics forms! This is one of the GMAT’s favorites).</span></p> <p><span style="font-weight: 400;">You might have recognized that the numerator could be simplified to (x+y)(x-y). Then the (x+y) canceled out of top and bottom, leaving you with just (x-y). But what about that first expression? The one you probably didn’t see how to simplify when given a minute?</span></p> <p><span style="font-weight: 400;">Turns out, it’s the exact same problem.</span></p> <p><span style="font-weight: 400;">Try it again. Specify what you did in the second, easier problem and try to replicate that same logic on the first.</span></p> <p><span style="font-weight: 400;">Maybe you realize that (x-y), though it doesn’t appear in the most common form of a difference of squares, can be written as ((√x)²</span><span style="font-weight: 400;"> – (√y)²</span><span style="font-weight: 400;">).</span></p> <p><span style="font-weight: 400;">This makes it look much more like the standard form of a difference of squares! We can now write it as (√x + √y)*(√x – √y). And then the (√x + √y) cancels on top and bottom, leaving just (√x – √y).</span></p> <p><span style="font-weight: 400;">How about:</span></p> <p><span style="font-weight: 400;">(3</span><span style="font-weight: 400;"><sup>2x</sup></span><span style="font-weight: 400;"> – 5</span><span style="font-weight: 400;"><sup>2x</sup></span><span style="font-weight: 400;">)/(3</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;"> + 5</span><span style="font-weight: 400;"><sup>x</sup></span><span style="font-weight: 400;">)</span></p> <p><span style="font-weight: 400;">Same logic. Different mask.</span></p> <p><span style="font-weight: 400;">This is partly why I warn my students that it’s not enough to just memorize a flashcard. It’s one thing to know the most general appearance of formula, and another thing to be able to recognize that it should be used when it has a mask on.</span></p> <p><span style="font-weight: 400;">What is x if x²</span><span style="font-weight: 400;"> = 4</span><span style="font-weight: 400;"><sup>30</sup></span><span style="font-weight: 400;">?</span></p> <p><span style="font-weight: 400;">What is x if x²</span><span style="font-weight: 400;"> = 36?</span></p> <p><span style="font-weight: 400;">If on the second you remembered to say ‘+/- 6’ but on the first you just said ‘4</span><span style="font-weight: 400;"><sup>15</sup></span><span style="font-weight: 400;">’ you fell for a GMAT mask. It’s like the least fun Halloween costume ever.</span></p> <p><span style="font-weight: 400;"><iframe src="https://giphy.com/embed/ctD357Rv3SCNG" width="480" height="363" frameBorder="0" class="giphy-embed" allowFullScreen></iframe></p> <p><a href="https://giphy.com/gifs/david-bowie-cracked-actor-gif-ctD357Rv3SCNG"></a></p> <p></span></p> <p><span style="font-weight: 400;">You’re used to solving the second equation, and you had ‘+/- 6’ drilled into you after all the times you forgot about it (and maybe you just did! Hey, don’t forget that on the GMAT, numbers can be negative unless specified otherwise). But 4</span><span style="font-weight: 400;"><sup>30</sup></span><span style="font-weight: 400;"> is weird. That’s a number we don’t deal with day-to-day, unless we happen to be God, and we’re counting all the stars for fun. So sometimes we let the appearance shake us.</span></p> <p><span style="font-weight: 400;">This doesn’t just happen in GMAT Quant. The Verbal section is full of masks. Masks are the fluff in Sentence Correction that separate singular nouns from plural verbs. </span><a id="bloglink" href="https://www.manhattanprep.com/gmat/blog/2018/08/07/gmat-verbal-fair-part-2/" target="_blank" rel="noopener"><span style="font-weight: 400;">They’re the arguments in Critical Reasoning that seem to be about different topics but are all actually about rates and totals, or questions of causation, or sample biases</span></a><span style="font-weight: 400;">. They’re in Reading Comp, because in all the myriad of topics in the passages they give you, </span><span style="font-weight: 400;"><a id="bloglink" href="https://www.manhattanprep.com/gmat/blog/2017/10/19/what-really-matters-gmat-reading-comp/" target="_blank" rel="noopener">they keep asking about the same stuff</a>.</span></p> <p><span style="font-weight: 400;">This is why on the GMAT, you have to review questions and specify the processes you used. Even on an easy question, you think you understand perfectly.</span></p> <p><span style="font-weight: 400;">You know that 60/12 is 5. But why? How deep can you get with that? If you can explain to me why 60 is divisible by 12 in terms of prime numbers—which are the heart of divisibility—you’ll be much closer to being able to explain to me how (60 * 35) is divisible by 28. If you can explain that, you can explain how 60! is divisible by 11</span><span style="font-weight: 400;"><sup>5</sup></span><span style="font-weight: 400;">, even though those numbers look so much more disgusting. But really? it’s all the same mask.</span></p> <p><span style="font-weight: 400;">60 is divisible by 12 because the prime factors of 12, 2*2*3, are also in the prime factorization of 60 (which are 2*2*3*5).</span></p> <p><span style="font-weight: 400;">(60*35) is divisible by 28 because the prime factorization of 28, 2*2*7, is also in the prime factorization of 60*35 (which is (2*2*3*5*5*7).</span></p> <p><span style="font-weight: 400;">60! is divisible by 11</span><span style="font-weight: 400;"><sup>5</sup></span><span style="font-weight: 400;"> because the prime factors of 11</span><span style="font-weight: 400;"><sup>5</sup></span><span style="font-weight: 400;">, (11*11*11*11*11), are also in the prime factorization of 60 (which is… well, it’s a very long list, but 60! = 1*2*3*4*5…*58*59*60, and 11 shows up 5 times in that product string, at 11, 22, 33, 44, and 55).</span></p> <p><span style="font-weight: 400;">How do you get good at seeing through masks? You have to really pinpoint why you’re doing process—even on an easy question where it seems obvious—and work to understand questions and concepts at their deepest level, not just at a superficial familiarity. And when something looks just </span><i><span style="font-weight: 400;">weird, </span></i><span style="font-weight: 400;">run through your rolodex of commonly tested rules or formulas and see if you can’t spot which one seems to ‘line up’ best with the situation at hand. Perhaps you’ll realize what you have in front of you is just a regular old process trying to disguise itself.</span></p> <p><span style="font-weight: 400;">Look past the masks, and you’ll often find the same old friends underneath. Superman’s glasses weren’t ever that effective a disguise, anyway. ? </span></p> <p><span style="font-weight: 400;"><iframe loading="lazy" src="https://giphy.com/embed/pqFbHWj0vRqmY" width="480" height="400" frameBorder="0" class="giphy-embed" allowFullScreen></iframe></p> <p><a href="https://giphy.com/gifs/superman-challenger23-pqFbHWj0vRqmY"></a></p> <p></span></p> <hr /> <p><b><i>Want some more GMAT tips from Reed? Attend the first session of one of his </i></b><a id="bloglink" href="https://www.manhattanprep.com/gmat/classes/#instructor/366" target="_blank" rel="noopener"><b><i>upcoming GMAT courses </i></b></a><b><i>absolutely free, no strings attached. Seriously.</i></b></p> <hr /> <p><em><strong><a id="bloglink" href="https://www.manhattanprep.com/instructors/reed-arnold/" target="_blank" rel="noopener">Reed Arnold</a><a href="https://www.manhattanprep.com/instructors/reed-arnold/?utm_source=manhattanprep.com%2Fgmat%2Fblog&utm_campaign=GMAT%20Blog&utm_medium=blog&utm_content=Reed%20Arnold%20Bio%20Link" target="_blank" rel="noopener"><img decoding="async" loading="lazy" class="alignleft wp-image-12946 size-thumbnail" src="https://d27gmszdzgfpo3.cloudfront.net/gmat/wp-content/uploads/sites/18/2017/01/reed-arnold-150x150.png" width="150" height="150" data-pin-nopin="true" /></a> is a Manhattan Prep instructor based in New York, NY.</strong> He has a B.A. in economics, philosophy, and mathematics and an M.S. in commerce, both from the University of Virginia. He enjoys writing, acting, Chipotle burritos, and teaching the GMAT. <a id="bloglink" href="https://www.manhattanprep.com/gmat/classes/#instructor/366" target="_blank" rel="noopener">Check out Reed’s upcoming GMAT courses here.</a></em></p> <p>The post <a rel="nofollow" href="https://www.manhattanprep.com/gmat/blog/gmat-masks/">The GMAT’s G-MASKs</a> appeared first on <a rel="nofollow" href="https://www.manhattanprep.com/gmat">GMAT</a>.</p> ]]></content:encoded> </item> </channel> </rss>