
The biggest "time killers" are those questions that I know I can solve if I spent a little bit more time on them. E.g. Spending 7-10 minutes. While wasting time on them, I keep getting the feeling that the solution was "around the corner" and refuse to give up. Also, having spent time reading the question, it feels like such a waste to let it go.
How do I know when to skip these? Spend 2 minutes per question, if I'm not rapidly approaching a solution, skip?
E.g. Those "which of the following is a metric" type question. We all know to check for triangle inequality, d(x,y) = 0 iff x = y etc. But I often get stuck thinking about how to disprove the triangle inequality for one of the options, after spending time eliminating 2-3 others.