Match each description with its symbolic representation. 1. p (a) the probability that both events a and b do not occur together, but either may occur by itself 2. p (a ∩ b) the probability that event a occurs 3. p (a ∪ b) the probability that neither event a or event b occurs 4. 1 - p (a ∩ b) the probability that event a occurs given the fact that event b occurs 5. 1 - p (a ∪ b) the probability that either event a or event b occurs 6. p (a | b) the probability that both event a and event b occur