Quantitative: In Depth

Of the total 37 questions on the quant section, you will see two different kinds: problem solving and data sufficiency.

Problem Solving

You have probably seen this type of problem all throughout studying math in school.  These types of questions simply lay out a problem for you to solve and give you 5 answer choices from which to chose.

Let’s look at an example:

Jeb and Carla start at opposite ends of a 10 mile trail and start jogging towards each other at the same time.  Jeb runs at a speed of 5 miles per hour and Carla runs at a speed of 3 miles per hour.  How many miles will Jeb have traveled when they cross each other?

o   1.25

o   2

o   4.5

o   5.8

o   6.25

 

Some important things to note: the answer choices are always from greatest to least, so if you are guessing and testing answer choices, start somewhere in the middle.

Always pay attention to what the question is asking. The GMAT often tries to trick you.  For example, 1.25 is the amount of time that it will take for Jeb and Carla to pass each other.  If you lose sight of what you are looking for when you are doing the calculations, you might see that answer, pick it and move on.  But you would be wrong and lose this point for a silly mistake.

Data Sufficiency 

Data Sufficiency is a little more complicated.  In a data sufficiency problem, you are given some information and a question and you have to figure out IF the problem can be solved based on that information.

Let’s look at an example with the same problem:

Jeb and Carla start at opposite ends of a 10 mile trail and start jogging towards each other at the same time. How many miles will Jeb have traveled when they cross each other?

(I) Jeb runs at a speed of 5 miles per hour

(II) Carla runs at a speed of 3 miles per

Your options for answers are:

A)   (I) alone is sufficient, but (II) alone is not

B)   (II) alone is sufficient, but (I) alone is not

C)    Both together are sufficient, but neither alone is sufficient

D)   Each statement is sufficient on its own

E)   Both statements together are not sufficient

What the test means by sufficient is, that information can be used to solve the problem or answer the question.   Pay attention to what the question asks, it could be as specific as the value (like this question), or it could be something more general, like: is X even?  Depending on how specific the question is, you will need more or less information to solve it.

Important to note: once you know if you can solve it or not, don’t bother actually solving it.  It’s a waste of time.  Put in your answer and move on.  Also, the order of the answers is the same every time so you should memorize it, so you can easily pick out which answer choice you are looking for.

What this means for studying:

The information you will need for both sections include: fractions, decimals, percents, number problems, combinatorics, geometry, algebra and number properties.