The Probability of Either X or Y Occurring: CFA Level 1 Exam

C

Note the relationship, P(X or Y) = P(X) + P(Y) - P(X and Y) Also remember that for mutually exclusive events, by definition, P(X and Y) = 0. Therefore, P(X or Y) =

0.15 + 0.32 = 0.47.

To determine the probability of either event X or event Y occurring, we need to consider the concept of mutually exclusive events.

Mutually exclusive events are events that cannot occur simultaneously. In other words, if event X happens, event Y cannot happen, and vice versa. This implies that the probability of both events occurring together is zero.

In this case, we are given the individual probabilities of event X and event Y occurring. P(X) = 0.15 and P(Y) = 0.32.

Since events X and Y are mutually exclusive, the probability of either X or Y occurring can be calculated by adding their individual probabilities:

P(X or Y) = P(X) + P(Y)

Substituting the given probabilities, we have:

P(X or Y) = 0.15 + 0.32

P(X or Y) = 0.47

Therefore, the probability of either event X or event Y occurring is 0.47.

The correct answer is C. 0.47.