There are n students in a class. Let P (E) be the probability that exactly out of n pass the examination. If P(Ex) is directly proportional to (0 n). 52. Proportionality constant k is equal to 1 1 n 1 (a). (b) (c) (d) 53. If P(A) be the probability that a student selected at random has passed the examination, then lim P(A), is (a) 0.25 (c) 0.75 54. If a selected student has been found to pass the examination, then the probability that he is the only student to have passed the examination, is 1 1 (a) (c) (b) 0.50 (d) 0.35 1 (b) 2 n 1 Ent (d)