If A and B are mutually exclusive events in some sample space S, and P(A) = 0.3 and P(B)= 0.5 find the probability that A occurs but B does not. Solution AS a and B are mututlly exclusive therefore , P(A B) = 0 only A occurs not B P(A - B) = P(a) - P(A B) = 0.3 - 0 0.3 answer !!!!.