Take notes and categorize topic areas. Study both the correct and incorrect answers for these, see why correct answer are correct and incorrect answers are not. As you learn the rules, write them down (I would suggest a program like Evernote). This will help you reference things later on and help you commit the rules to memory. Good luck.
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Jim Kernan is the Director of GMAT Operations at Stratus Prep and author of GMAT Materials for GMAT Prepster.