splitting up

Depends on the type of exam. If each question is worth the same amount, you divide the total time by the number of questions. That is how long you have to spend on each question. When time is up, you move on to the next question, done or not. If you have time left over at the end, you can come back and guess. If all questions are not equal, divide the time based on the importance of the question. Basically, determine how long you have to spend on each question and ONLY SPEND THAT MUCH TIME. When time is up, move on. You must disciplined. If you are not disciplined and spend even a few extra seconds "getting a question" you will run out of time.