We have
probability of B occurs is 5/8
probability that event A occurs given B occurs is 5/8
We have the next formula, that is the conditional probability formula
where
P(A|B)= probability of A given B
P(B)= probability of B
P(A∩B)=probability of A and B
so we need to isolate the P(A∩B) in order to obtain the probability that events A and B both occur