True or false:

a) If two events A and B are mutually exclusive, the probability that either A or B occurs is 1.

b) If two events A and B are mutually exclusive, conditional probabilities satisfy P(B|A) = P(A|B).

c) Suppose events A and B are mutually exclusive.Suppose events C and D are such that P(A)=P(C) and P(B)=P(D).Then, we have P(A or B) <= P(C or D).

d) Suppose S is a strictly positive random variable and b is a constant such that b>1.Define T=b*S.Then, E(T)/E(S)=b.

e) Suppose S is a strictly positive random variable, and b is a non-zero constant.Define T=b*S.The standard deviations, denoted by STD, satisfy STD(T)/STD(S)>0.

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