Before reading the passage read the question first to determine what information you need. Reread the question slowly and carefully. Find the assumption and conclusion of the passage, and be aware that they may not be written in a normal or easy to find order. Key words that may signal the conclusion include "consequently," "as a result," "hence" or "thus." Before reading the answer choices, try to come up with the answer yourself. Then read each answer carefully. Eliminate the ones you are certain are wrong. Typically, one answer will stand out as exactly opposite to the correct one. Find that one and eliminate it. Once you've narrowed down the answers, insert each one into the passage to see which works best and makes the most sense.
Eliminate answers written in absolute terms such as always or never. Test writers avoid such statements. Similarly, avoid emotional or inflammatory type answers. GMAT answers are neutral in tone. Avoid choosing an answer because it is true. The answer must be accurate according to the argument presented in the passage. Weed out superfluous or unnecessary information as it only will distract from the important information.
To prepare for the critical reasoning section of the GMAT, understand the different types of questions employed.
Support or strengthen questions will contain words such as "strengthen," "support," or "credibility." Look in these questions for an answer that supports the passage's conclusion.
Oppose or weaken questions are signaled by words such as "weaken," "oppose" or "nullify," and in these seek answers that oppose the conclusion presented in the selection.
In assumption questions you look for answers that provide essential support to the passage's conclusion.
Logic pattern questions are quite specific. The question will ask you to figure out how the conclusion is determined, and it requires careful reading.
Analysis questions have no key signaling words and require close reading to determine the answer. Explanation questions will often use the word "explain" and will require an answer to what is missing or contradictory in the passage.
Many books and practice tests are available online to enable test-takers to practice identifying the types of questions on the GMAT critical reasoning section.