Final answer:
The probability of A or B occurring is 0.80.
Step-by-step explanation:
For mutually exclusive events A and B, the probability (P) that at least one occurs (A or B) is (PA + PB). In this case, we know that PA = 0.35 and PB = 0.45. Therefore, P(A∪B) = PA + PB = 0.35 + 0.45 = 0.80.