In the quantitative section of the GMAT, about 15 of the 37 multiplechoice questions are datasufficiency questions, and the remaining 22 are problemsolving questions. These two types of questions are intermingled throughout the quantitative section.
Datasufficiency questions test your knowledge of three subject areas: arithmetic, elementary algebra, and geometry. The number of questions for each of these three subjects is roughly
 Arithmetic: 8
 Elementary algebra: 4
 Geometry: 3
Datasufficiency questions are multiplechoice questions with five answer choices. These questions, however, do not require you to find a solution to the problem. Instead, you need to exam the given data and determine which of the given data provides sufficient information to solve the problem. The format of datasufficiency questions is as follows:
You are given a problem accompanied by two statements labeled (1) and (2). Based on the information, you must select one of the following choices:
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.
When solving dataefficiency questions, remember the following:
You don't have to solve the problem. You only need to determine whether the given information is sufficient to solve the problem according to the answer choices.
When a question asks for the value of a quantity, it is considered sufficient only if you can determine exactly one value for the quantity.
As with the rest of the quantitative section, all figures are drawn as accurately as possible to match the information in the problem, unless indicated otherwise. However, in datasufficiency questions, the figure may not match the information given in statements (1) and/or (2).
Straight lines may appear jagged on the computer screen.
All numbers used are real numbers.
When working on the quantitative section of the GMAT, keep in mind the following:

It is important to pace yourself. You have 75 minutes to do 37 questions, which is approximately 2 minutes per question.

You may not skip over a question. The computer will not present the next question until you've answered the current one on the screen.

Make an educated guess if you aren't sure about the answer. There is a penalty for wrong answers, but there is also a penalty for unanswered questions, so if you're struggling with a particular question, you're better off making an educated guess and moving on.
 Calculators are not allowed.