Monday Mail-Bag: Advice on Big Picture Issues That Impact GMAT Test Takers…

By - Aug 1, 12:01 PM Comments [0]

by Rich Cohen, Rich.C@empowergmat.com  www.EMPOWERgmat.com

This series of emails and PMs focuses on situations that many Test Takers face during their studies. The names of the original posters have been changed to protect their identities.

Data Interpretation Comes in Many Forms on Test Day
Hi Rich,

To what degree is data interpretation tested on the gmat?

Roosevelt

Hi Roosevelt,

Are you referring to DS questions, IR questions or chart/graph/table questions?

DS questions make up a considerable portion of the Quant section (you'll see about 15 on Test Day). While the IR section does include a variety of "table" questions to deal with, the Quant section usually includes 1 prompt that will include a graph or table of data. That one question in the Quant section often takes longer than average to solve, so you have to be prepared to put in a bit more effort when it shows up.

Effective Use of Time Per Question in the Quant Section
Dear Rich,

Some questions I am able to solve and move quickly through, others I find I am spending a lot of time on. Do you have a breakdown of what too much time on questions is?

Sherman

Hi Sherman,

When assessing the amount of time that you're spending on an individual question, you should define exactly what you're DOING with your time. If you're staring at the screen, then you're wasting time. If you honestly can't figure out what to do with a question, then you're wasting time. When you DO answer a question correctly, you should think about HOW you solved it and if that method was actually fastest. Most questions can be solved in a number of different ways, so you might want to ask yourself if your way was FASTEST.

Most pacing problems occur because of bad decision-making. Instead of restricting yourself to a particular amount of time per question, put your emphasis into proper note-taking and organization and learning the various approaches to each type of prompt. Also, you have to be mentally prepared to quickly "dump" a question if you can't figure out how to deal with it.

Dealing With Symbolism Questions on Test Day
Rich,

I faced this PS question below that I couldn't overcome.. Can you give me a way out?

For any numbers a and b, a · b = a + b - ab.
If a · b = 0, which of the following CANNOT be a value of b?

(A) 2
(B) 1
(C) 0
(D) -1
(E) -2/3

I hope you can explain me how to solve this question!

Truman

Hi Truman,

This is an example of a Symbolism question (and you'll likely see 1 on Test Day). The idea is that you'll be given a "made up" math symbol, told what it "means" mathematically and then asked to solve some minor equation.

Here, we're told to substitute values in for A and B so that the equation….

A + B - AB = 0

We're asked which of the following answers CANNOT be the value of B? So 4 of the answers are POSSIBLE and one is IMPOSSIBLE.

There are a couple of ways to approach this prompt. You could work mathematically or you can TEST THE ANSWERS. I'm going to use the answers to my advantage and find the 4 that are possible solutions and the one the creates an impossible situation:

If B = 2, then we'd have...
A + 2 - 2A = 0
2 = A
So B COULD be 2

If B = 1, then we'd have…
A + 1 - A = 0
1 = 0???????
B CANNOT equal 1

At this point, we could stop. Answer B is clearly the one that is NOT possible, so it must be the answer. I'll show you why the other answers are possible though:

If B = 0, then we'd have…
A + 0 - 0 = 0
0 = A
So B COULD be 0

If B = -1, then we'd have…
A -1 -(-1)(A) = 0
2A = 1
1/2 = A
So B COULD be -1

If B = -2/3, then we'd have…
A - 2/3 -(-2/3)(A) = 0
A + 2A/3 = 2/3
5A/3 = 2/3
A = 6/15
So B COULD be -2/3

Final Answer: B

GMAT assassins aren't born, they're made,
Rich

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