中等MATH-PROB-004
A and B are independent, with P(A) = 0.5 and P(B) = 0.4. What is P(A ∩ B)?
A. 0.9
B. 0.1
C. 0.45
D. 0.2✓ 答案
解說
For independent events the joint probability is the product: 0.5 × 0.4 = 0.2. Adding the probabilities gives the wrong rule for an intersection.