Prepare by becoming familiar with the different types of questions used in the GMAT critical reasoning sections. These include assumption questions, method of reasoning questions, strengthen or weaken the argument questions, inference questions, resolve the paradox questions and evaluate the argument questions. Once you know the type of question you're facing, you will be able to narrow down the possible correct answers. Also prepare by understanding logic terms such as assumption, inference, paradox, conclusion and evidence.
Aim for taking no more than two minutes per question, as managing the clock is a crucial skill in taking the GMAT. Look for neutral or moderately worded answers. Answers that are absolutes are unlikely to be the correct ones, so look out for words such as "never," "always" or "must." Carefully read the question; typically, the opposite of the correct answer will be among the choices to throw off students who didn't read the question closely enough.
Certain reasoning methods are typically more effective and therefore more likely useful in the GMAT critical reasoning questions; these include referring to an authority or using an analogy. Countering arguments may be accomplished by citing ulterior motives, showing logical inconsistency or pointing out consequences not identified.
For methods-of-reasoning questions, look for answers that use statistics, cause and effect or analogies. For questions that ask for a conclusion, look for an answer that contains elements of all the question's premises. However, an inference question typically involves just one of the premises from the argument. Strengthen-the -argument questions will require an answer that strengthens the argument with new information that supports the conclusion of the passage. Resolve-the-paradox questions will be correctly answered by a choice that lets both of the facts from the question be true.