Just to put this question in context, I have been preparing for the GRE for months now, I've been developing a strategy to maximize my score regardless of what my knowledge of physics is or isn't. I'm not asking for basic advice. The only part of my analysis that is lacking is trying to determine the optimum number of questions to attempt, or put another way, how many questions should you outright skip completely with no attempt at trying. I do not believe the optimum number is all 100, for several reasons. First, you should focus on your strengths, and topics you're already weak on to begin with are not worth wasting time with (since you're more likely to get it wrong anyways). Second, you only need a raw score of about 65 to get a good score on the exam - that leaves room for skipping quite a few questions (though you do need some cushion for getting questions wrong). Skipping some questions means you have more time to work on those you feel you know how to do, and means you're less likely to make a mistake. I would guess that if you plotted your average raw score (assuming you had many exams to take and took them far enough apart that taking one didn't influence your score on another), versus the number of questions you actually attempted (without randomly guessing), then it would peak somewhere around 80 questions attempted. That number just comes from my own feeling of doing the exams and knowing what doing 80 feels like, and it seems like a good number. I could be wrong though, it could actually be lower, or maybe higher. Anyone have thoughts or opinions on this?