GMAT Data Sufficiency: Know the Test

September 28, 2006

If you’ve been studying for the GMAT for a long time, you probably know the Data Sufficiency answer choices like the back of your hand. If you don’t, you should! Even if you haven’t been studying for very long, it’s important to internalize what the choices are and what they mean: there’s no excuse for wasting time on test-day reading over answer choices that you’ve been looking at for weeks.

As a quick review, here’s what the answer choices will always look like:

(A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

(B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

(D) EACH statement ALONE is sufficient.

(E) Statements (1) and (2) TOGETHER are NOT sufficient.

It’s a mouthful–not to mention the fact that it looks like the choices are shouting at us. Take out the capitalized words, and they really aren’t complicated concepts.

One of the benefits of knowing the Data Sufficiency answer choices well is that, each time you evaluate a statement, you can eliminate a few choices. Consider the following:

  • If Statement (1) is sufficient, (B), (C), and (E) are eliminated.
  • If Statement (1) is insufficient, (A) and (D) are eliminated.
  • If Statement (2) is sufficient, (A), (C), and (E) are eliminated.
  • If Statement (2) is insufficient, (B) and (D) are eliminated.

Even if you can only evaluate one statement, you can guess from among 2 or 3 choices instead of 5. That in itself could be worth an extra question or two to you over the course of the 37 question (about 13 Data Sufficiency) GMAT Quantitative section.

There are two more ways you can eliminate choices. These are a little more complicated, and I’ll focus on them in future tips.

  • If Statements (1) and (2) say the exact same thing, (A), (B), and (C) are eliminated.
  • If a statement repeats something that the question tells you, or provides no information whatsoever, that statement’s choice [(A) or (B)] and (C) are eliminated.

But before you can internalize these rules, you have to internalize the answer choices. Next time you work through a set of Data Sufficiency problems, force yourself to stop after you evaluate each statement and figure out which answer choices you can eliminate. It’ll slow you down for a day or so, but after a few dozen questions, it’ll be automatic. Just as it should be.

Jeff Sackmann is a GMAT tutor based in New York City. He has created many resources for GMAT preparation, including the popular GMAT Math Bible and GMAT Verbal Bible, as well as 1,800 practice GMAT math questions.

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