About 1/3 of the 37 questions in the GMAT Quantitative section will be Data Sufficiency questions. They will probably be unlike any math problems you have seen before, since GMAT Data Sufficiency questions have a unique format. And unlike most math questions, they test your ability to determine what information is needed in order to solve a certain question, rather than your ability to find the solution. In general, Data Sufficiency questions take less time to answer than Problem Solving questions as you don't actually have to solve them but only have to determine what information is sufficient to do so.
Format of Data Sufficiency Questions
Each question consists of a question stem, 2 statements and 5 answer choices. You don't need to solve the problem; you only have to find out whether information provided by the 2 statements is sufficient to solve it. For all Data Sufficiency questions, answer choices are the same and in the same order:
A) Statement (1) ALONE is sufficient, but statement (2) is not sufficient.
B) Statement (2) ALONE is sufficient, but statement (1) 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.
(We have labeled the answer choices A-E but on your GMAT exam they will not be labeled with letters)
To save time you have to learn what is stated in each answer choice. You must be able to eliminate choices B, C, E without hesitation once you prove that statement (1) alone is sufficient. Similarly, you must know that you can eliminate choice A and D, if statement (1) is not sufficient. This is a very important feature of GMAT Data Sufficiency questions, as reading those answer choices every time and trying to understand what each of them means can be very time-consuming, so make sure you know what each answer choice says and what answer choices can be eliminated once you prove one of the statements sufficient or insufficient. The best way to do this is to solve as many Data Sufficiency problems as possible.
To determine what information provided by the 2 statements is sufficient to answer the question, you can use information provided in the question, information provided in the statements, your knowledge of math and everyday facts, such as the number of months in the year and their order, number of minutes in one hour, etc.
- How to Approach GMAT Data Sufficiency Questions
- Sample GMAT Data Sufficiency Questions
- GMAT Math Section
- How to Improve Your GMAT Math Score
- Avoiding the Most Common Mistakes on GMAT Data Sufficiency Questions