Final answer:
The probability of the union of mutually exclusive events A and B is the sum of their individual probabilities, which in this case is 1.0.
Step-by-step explanation:
When two events are mutually exclusive, it means that they cannot occur at the same time. In this case, events A and B are mutually exclusive. To find the probability of the union of events A and B, we simply add the probabilities of the individual events. So the probability of A or B occurring is P(A) + P(B).
Given that P(A) = 0.4 and P(B) = 0.6, we have:
P(A or B) = P(A) + P(B) = 0.4 + 0.6 = 1.0
Therefore, the probability of the union of events A and B is 1.0.