Navigating the GMAT Data Sufficiency Maze

Data sufficiency questions all seek to determine the same thing: Can you answer the question with the information you've been given?

Data sufficiency problems make up about two-fifths of the quantitative questions on the GMAT. These questions are probably not like any test problem you've encountered before. They don't ask you to answer the question. Instead, they ask you to determine whether or not you can answer the question with the information given. Here is an example:

What is the minimum GMAT score, on the 200-800 scale, that an applicant must have in order to gain acceptance to the UltraTech Management School?

(1) The UltraTech Management School charges $8,000 per semester for tuition.

(2) The UltraTech Management School accepts any applicant who has taken the GMAT and paid the application fee.

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.

All data sufficiency questions offer you the same five answer choices. You need to memorize these answer choices before you walk into the test. In fact, do it now.

The fact that every data sufficiency question offers the same answer choices means that you can approach each one the same way. You read the question stem. You figure out what it's asking. Then you read statement (1). From here on, it's AD or BCE.

What this means is that if statement (1) is sufficient, then the answer to the question will be either A or D. If statement (1) is not sufficient, then the answer to the question will be B, C, or E.

Every data sufficiency question should be answered by continuing with the same technique. Simply by determining the sufficiency of just one statement, you should be able to eliminate approximately half of the answer choices. That way, you should be able to avoid completely random guessing on data sufficiency questions.

Adapted from McGraw-Hill's GMAT, by James Hasik, Stacey Rudnick, and Ryan Hackney. Book-only and book-CD-ROM versions available wherever books are sold.