CA Foundation · Quantitative Aptitude · Probability
Two events A and B are independent with P(A) = 0.4 and P(B) = 0.5. What is the probability that both A and B occur?
The probability that both events occur is 0.20. For independent events the multiplication theorem says P(A and B) equals P(A) times P(B), so 0.4 multiplied by 0.5 gives 0.20. Adding the probabilities would be incorrect.
- A0.90
- B0.20Correct
- C0.10
- D0.45
Explanation
For independent events, P(A and B) = P(A) × P(B) = 0.4 × 0.5 = 0.20. The option 0.90 is the sum of the probabilities, which wrongly adds instead of multiplying.
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