Question Format and Structure

Learning Objective

In this section, you will learn how to: 

• Describe some key features of Data Sufficiency questions and answer choices

The instructions for Data Sufficiency questions on the GMAT look like this:

1. Directions: In each of the problems, a question is followed by two statements containing certain data. You are to determine whether the data provided by the statements are sufficient to answer the question. Choose the correct answer based upon the statements’ data, your knowledge of mathematics, and your familiarity with everyday facts (such as the number of minutes in an hour or cents in a dollar). You must indicate whether:
   1. Statement (1) ALONE is sufficient, but Statement (2) is not sufficient.
   2. Statement (2) ALONE is sufficient, but Statement (1) is not sufficient.
   3. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
   4. EACH statement ALONE is sufficient.
   5. Statements (1) and (2) TOGETHER are NOT sufficient.

Note: Diagrams accompanying problems agree with information given in the question but may not agree with additional information given in Statements (1) and (2).

All numbers used are real numbers.

The GMAT is the only test featuring Data Sufficiency questions, and beginners often misunderstand the format. On the Quantitative section, you’ll see about 14 Data Sufficiency questions, which ask you to assess whether certain statements provide enough information to answer a question. Often, the question requires little or no mathematical work. The key to solving the question is understanding how the question type is structured and using that knowledge to work efficiently.

The directions may seem confusing at first, but they become clear with use. Let’s walk through a simple example:

1. 

   What is the length of segment AC?
   1. B is the midpoint of AC.
   2. AB = 5
   1. Statement (1) ALONE is sufficient, but Statement (2) is not sufficient.
   2. Statement (2) ALONE is sufficient, but Statement (1) is not sufficient.
   3. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
   4. EACH statement ALONE is sufficient.
   5. Statements (1) and (2) TOGETHER are NOT sufficient.

The diagram tells you that there is a line segment AC with point B somewhere between A and C. You’re asked to figure out the length of AC.

Statement (1) tells you that B is the midpoint of AC, so AB = BC and AC = 2AB = 2BC. Since Statement (1) does not give an actual value for AB or BC, you cannot answer the question using Statement (1) alone.

Statement (2) says that AB = 5. Since Statement (2) does not give you any information about BC, the question cannot be answered using Statement (2) alone.

Using both of the statements together, you can find a value for both AB and BC; therefore, you can solve for the length of AC, and the answer to the question is choice (C).