please help me i hate probabilty!

Two students Alan and Brenda are due to take an examination. The probability that Alan will pass is 3/5 the probability that Brenda will fail is 4/7.

a) calculate the probability that both will fail

b) calculate the probability that only one will pass

c) if Brenda fails the probability that she will pass next time is 2/5

(i) calculate the probability that Brenda fails again

(ii) calculate the probability that Brenda passes having taken the examination for a second time