If and are two events in a sample space of a random experiment, where , , and , find .
The notation refers to the probability of the occurrence
of and the non-occurrence of . Also, the notation refers to the probability of events and
occurring together. For this reason, is equal to the sum of
and . First, use this fact to
solve for .
The notation refers to the probability of
either event or event occurring, or both. If and
are two non-mutually exclusive events, then . Now use this fact to determine .
Thus, is equal to .