I revised for 10 weeks before my summer exams, for 5 before the winter. I should have done more for the winter. Essentially just think how long the course is for the particular module, do a test paper (a past one) and judge on that. 10 weeks seemed okay for me, but saying that I am very determined with these kind of things. Doing it for longer means You can space it all out, sit down and write a plan for the whole ten weeks , say with a sub a night or a part of each every night. For my a2 exams i managed AAB with an a in biology a/s (taken as an extra) and a resit a in a/s chemistry. I could have made it triple A but it was becuase I didnt spend enough time on chemistry, focusing too much on psychology. Also divide the time between the subjects dependent on your strengths, i.e I was strongest at Psychology but revised it the most, securing an A. Same with Physics.
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