中等MATH-PROB-003
If A and B are mutually exclusive, which statement must be true?
A. P(A ∩ B) = 0✓ 答案
B. P(A ∪ B) = P(A)P(B)
C. P(A | B) = P(A)
D. Both events have probability 1/2
解說
Mutually exclusive events do not occur together, so the intersection has probability 0. The product formula and P(A | B) = P(A) are independence, which is a different condition.