GMAT Quantitative Reasoning Skills - Data-sufficiency

The quantitative section of the GMAT consists of two primary types of questions, which includes problem-solving questions and data-sufficiency questions. The data-sufficiency questions on the exam are designed to evaluate an individual's ability to identify which information is relevant to solving a particular problem and ultimately which information is necessary to solve the problem. In other words, these questions examine whether or not an individual can determine if a particular piece of information relates to the problem and, if that information is related, is that information required in order to solve the problem. Each of these questions will present the individual with a question or problem and two statements that the individual must analyze and decide whether the first or second statement is enough to solve the problem, both statements are required to solve the problem, either statement by itself could be used to solve the problem, or both of the statements do not offer enough information. For example, the individual might be presented with a question such as "is x equal to 15?" and two statements such as:

• (1) x is an integer less than 16
• (2) x is an integer greater than 14

The individual would than have to choose the option that indicated that both statements together are required to solve the problem as neither statement is sufficient to answer the question alone. However, by using both statements together we find that x must be an integer between 14 and 16 so therefore it must be 15. The exam-taker will usually be presented with approximately 12 to 14 of these multiple-choice data-sufficiency questions on the exam.