The data-sufficiency questions on the GMAT are specifically designed to determine whether or not an individual is capable of analyzing a problem and ultimately identifying which information is necessary and which information is not necessary to solve the problem. However, there are certain key concepts about the data-sufficiency questions on the exam that an individual might want to keep in mind while taking the exam. First, do not assume anything about the information provided in the data-sufficiency questions on the exam.
Each data-sufficiency question is completely separate from every other question on the exam and the information provided in the question is the only information you should pay attention to. If you are certain that the information provided is related to a previous question, you can identify the size of a figure or a part of figure simply by looking at it, or you can assume that the statement must be true because of some other standard assumption, the best course of action is to forget the assumption and use the information provided. The exam’s designers will use these common assumptions against you and they have designed the data-sufficiency questions to determine whether or not you can distinguish unfounded assumptions from logical, well-founded solutions.
Secondly, look at the statements provided in each data-sufficiency question carefully and make sure that you understand what each statement is actually stating. The exam’s designers have written most of the data-sufficiency statements on the exam so that they deliberately indicate certain assumptions, but do not specifically state them or so that the statements attempt to trick you in some other way. For example, some of the data-sufficiency questions on the exam might present you with two statements that mean exactly the same thing, but are just stated in a slightly different format. The most important thing to keep in mind in order to correctly answer the data-sufficiency questions on the exam is that you must identify what the statements actually say and how they relate to the question itself rather than what they imply.