For that your mind should be stable.
Whatever you read that should fit in in your mind. This happens only in stable mind. For stable mind you have to meditate. Wake up early wash your face and sit in open environment. Then do not think anything. Just notice your breaths. Analyse your breaths rate them and soon you will reach to state. Everything calm, quiet, try to be in that state for 5 Minutes. Then go to your study table and study only those topics which from which questions were frequent in previous exams. Try to write them. Study only concentrated topics that are more scoring.