Let A, B, and C be events.
(a) Express the event D that only one of A, B, or C occurs using set operations
and draw the corresponding Venn diagram.
(b) Assume A ∪ B ∪ C = Ω. For any two among A, B, and C, let the probability that they occur simultaneously be 1/4. Let the probability that they all occur simultaneously be 1/8. What is the probability of D?