Comment by dejaime

Sometimes the material is absolutely unhelpful when doing a badly designed test, and you may even fail them. I had a Calculus teacher that taught 100% from the books but his tests were always 5 special case questions, that you might very well get wrong in under 45' even if you know the bread and butter.

Still learning how to do "Professor X's questions" was a guaranteed ace. Forget the subject, memorize the borderline cases, max grade. Do all exercises on the text book, also, get a second text book and do all of those too, and you might fail the test.