Invest some seconds over a question and study the question carefully. A brief explanation of why each choice is correct or incorrect should go into your mind. If you can practice this tip in sample reasoning questions, you will do well on the actual assessment.
NEVER assume or use any information that the question fails to give you. This is NOT an assessment of how much you know about a subject in general! Consider ONLY the information given in each reading passage when choosing among the alternative responses.
Read both the factual passage and the sentence completion instruction carefully. Both must be considered in making your choice.
Be sure to read all the response choices carefully before eliminating or choosing one of them.
In questions that ask you to select a valid conclusion, always choose the one conclusion that must definitely follow the information you are given. In questions that ask you to find the invalid alternative, choose the one conclusion that does not definitely follow from the information.
Pay special attention to words like "all," "some," or "none" when you read the factual information each question gives you. Other qualifying words such as "other than," "only" or "unless" are important, too. These words can play a critical part in precisely specifying the facts to be used in your reasoning.
Pay attention to negative prefixes also, such as non-, un-, or dis-. These can be crucial to specifying the basic facts in the paragraph.
You should also be very careful if any response choices that contain the quantifiers "all" or "none". Generally, in both the sample practice questions and in the actual CAT assessment, these words are NOT signs of incorrect response choices. They will appear in both correct and incorrect response choices.
Pay close attention to the word "ONLY" and to the phrase "IF AND ONLY IF". Saying "The car lock will open IF AND ONLY IF original keys are used" sets up a highly specific condition that must be met. There is exactly one way to open the car lock - you must use the original keys of the car. By contrast, if the sentence says, "The car lock will open if the original key is used," there may be several ways to open the car lock besides using the original key.