4 Common Types of Data Sufficiency Traps
If the GMAT were a sport, it would definitely be baseball, and not just because it’s three and a half hours long. In baseball, you might dominate the minor league by hitting fastballs, but once you reach the show you’ll have to hit some change-ups and curveballs too. Not only is the GMAT going to throw you some hard problems, but once you start to do well, the GMAT will throw you something different. That’s why learning the types of trap answers can help you from falling for them. Here’s four types of curveballs that you want to be mindful of on test day.
If you test it, they will come.
Challenge Problem Showdown – July 30th, 2012
We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!
Here is this week’s problem:
In the country of Celebria, the Q-score of a politician is computed from the following formula:
Q = 41ab2c3/d2, in which the variables a, b, c, and d represent various perceived attributes of the politician, all of which are measured with positive numbers. Mayor Flower’s Q-score is 150% higher than that of Councilor Plant; moreover, the values of a, b, and c are 60% higher, 40% higher, and 20% lower, respectively, for Mayor Flower than for Councilor Plant. By approximately what percent higher or lower than the value of d for Councilor Plant is the corresponding value for Mayor Flower?
Challenge Problem Showdown – July 23rd, 2012
We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!
Here is this week’s problem:
X is a three-digit positive integer in which each digit is either 1 or 2. Y has the same digits as X, but in reverse order. What is the remainder when X is divided by 3?
(1) The hundreds digit of XY is 6.
(2) The tens digit of XY is 4.
Are You Taking Too Many Practice GMATs?
My GMAT students are often surprised when I advise them not to take a practice test.
I don’t advise this for every student on every occasion; there are some legitimate uses for practice tests. In general though, I find that my students take too many practice tests at the expense of other more beneficial forms of study for a given circumstance.
Think of the GMAT like a Mozart sonata. Let’s say you are a pianist, and you want to learn the sonata. Would you begin by playing the whole piece from start to finish? No, instead you would work in small sections. You would identify the sections that are easy, and you would work on those sections just enough to maintain your ability. Mainly, you would be concerned with the difficult sections of the piece, which you would practice slowly and intently. Not until you had mastered those sections would you move on.
After you have put in all that practice time, you want to make sure that you can maintain your ability within the context of the larger piece. That’s when you want to play the whole piece: when you want to check to see whether your prior work is ingrained or whether you forget it when you are distracted by the other demands of the piece.
Flaw Questions on GMAT Critical Reasoning
We’ve talked about various types of Assumption Family questions in the past (find the assumption, strengthen, weaken, and evaluate the conclusion), but we haven’t yet tackled a Flaw question. This is the least frequently tested of the 5 Assumption Family question types, so you can ignore this type if you aren’t looking for an extra-high score. If you do want an 85th+ percentile verbal score, though, then you have to make sure you know how to tackle Flaw questions.
If you haven’t yet, read this article before we try our GMATPrep problem. Then set your timer for 2 minutes and go!
GMAT Lessons from Detective Shows
When not providing insight into the fascinating world of the GMAT, I enjoy watching detective shows on television. In many episodes, one of the detectives must delve into the mind of the perpetrator “ actually try to think as the perpetrator does. In so doing, the seemingly random clues come together (often via a slow motion or black and white flashback scene) leading to an insight that breaks the case.
I am going to advocate taking on this television detective mentality in approaching GMAT problems. Perhaps there is a further parallel as the mind of the GMAT question writer may seem to be just as scary a place as the mind of a criminal. But the ability to think like a GMAT test writer can provide multiple benefits including enabling you to get more questions right and allowing you to have more confidence in your answers.
So let’s try think about three lessons we can take from our favorite crime dramas and apply to the GMAT.
Challenge Problem Showdown – July 16th, 2012
We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!
Here is this week’s problem:
A decade is defined as a complete set of consecutive nonnegative integers that have identical digits in identical places, except for their units digits, with the first decade consisting of the smallest integers that meet the criteria, the second decade consisting of the next smallest integers, etc. A decade in which the prime numbers contain the same set of units digits as do the prime numbers in the second decade is the
The Most Important GMAT Question I Ever Studied
Every Manhattan instructor is probably able to fondly recall the Official Guide book that they used to ace their GMAT. Or at least that’s what I would have used to say. Now I know that every Manhattan instructor is probably able to fondly recall the Official Guide book that he or she used to ace his or her GMAT. For me it was the school bus-yellow 11th edition that included the most important question I ever studied. If you have the 12th edition of the Official Guide, it’s question #124. The answer choices on this question began with the following split:
sloths hang from trees…
vs
the sloth hangs from trees…
Decoding the Prime Disguise
How can the GMAT disguise a prime number (or any other) problem? I asked this question a couple of years ago at the start of a very important article entitled Disguising “ and Decoding “ Quant Problems. Go read that article right now, if you haven’t already. I’ll wait.
Towards the end of that article, I referenced two Official Guide problems. I was very excited today to see that one of these problems is part of the free practice problem set that now comes with the new GMATPrep 2.0 software “ so I can actually reproduce it here and we can try it out!
Disclaimer: this is a seriously challenging problem. Set your timer for 2 minutes, but practice your 1 minute timing here. If you don’t have a pretty good idea of what’s going on by the halfway mark, try to figure out how to make a guess. Pick an answer by the 2 minute mark (all right, I’ll let you go to 2 minutes 30 seconds if necessary “ but that’s all!).
Does the integer k have a factor p such that 1 < p < k?
(1) k > 4!
(2) 13! + 2 < k < 13! + 13
Challenge Problem Showdown – July 9th, 2012
We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!
Here is this week’s problem:
If a, b, and c are nonzero integers and z = bc, is az negative?
(1) abc is an odd positive number.
(2) | b + c | < | b | + | c |