Question 465430
a)  Two events A and B are mutually exclusive if P(A) + P(B) = P(A U B).
P(A) + P(B) = 1/4 + 2/5 = 13/20, but P(A U B) = P(A or B) = 1/2, so {{{P(A) + P(B) <> P(A U B)}}}, so A and B are not mutually exclusive.

b) P(A and B) = P(A) + P(B) - P(A or B) = 3/20 = 0.15

c) Two events A and B are independent if P(A)*P(B) = P(A and B).
 {{{1/10 = P(A)*P(B) <> P(AandB) = 3/20}}}, so A and B are not independent.