How do I work this problem?  Need detail because I have several to do Events A a

How do I work this problem?  Need detail because I have several to do
Events A and B are mutually exclusive.  Suppose event A occurs with probability 0.62 and event B occurs with probability 0.3.
a) Compute the probability that A occurs but B does not occur.
b) Compute the probability that either A occurs without B occurring or A and B both occur.