how many questions do I study out of the 5 given to me when only 3 are given on the exam and I have to only answer 2?
In some subjects you learn to game the system, and in some subjects you just learn the material. It sounds like you have a subject where you just learn it. Do the assignments right after they are assigned, instead of right before they are due. That way test time is a non-event because you are always perfectly prepared.