CA Foundation · Quantitative Aptitude · Probability
Two events A and B are mutually exclusive with P(A) = 0.35 and P(B) = 0.45. What is the probability that neither A nor B occurs?
For mutually exclusive events the probabilities simply add: 0.35 + 0.45 = 0.80 for at least one occurring. The probability that neither occurs is the complement, 1 - 0.80 = 0.20. Multiplying would wrongly assume independence.
- A0.80
- B0.20Correct
- C0.1575
- D0.65
Explanation
Mutually exclusive means P(A and B) = 0, so P(A or B) = 0.35 + 0.45 = 0.80. Neither occurs with probability 1 - 0.80 = 0.20. The value 0.1575 is the product, wrongly assuming independence.
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