Study all notes, reread the chapters again. Have someone ask questions on the chapters page by page. This always has worked for me. Plus try to do this again the night before the test. You will be surprised how much you can remember by doing it again the night before the test. Hope this helps.
By definition of conditional probability,
P(B | A) = P(A ∩ B)/P(A) = (13/25) / (13/20) = 20/25 = 4/5
√29/2 since cotangent deals the reciprocal of tangent and cotangent value is adjacent side/opposite side