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If P(A) = 0.4, P(B|A) = 0.5, then P(A ∩ B) equals
A{'text': '0.9', 'label': 'A'}
B{'text': '0.2', 'label': 'B'}
C{'text': '0.1', 'label': 'C'}
D{'text': '0.8', 'label': 'D'}
Answer & Solution
Correct answer: B. {'text': '0.2', 'label': 'B'}
1. By the multiplication rule, P(A ∩ B) = P(A) × P(B|A).
2. Substitute: P(A ∩ B) = 0.4 × 0.5.
3. = 0.20.
4. Note: P(A ∪ B) would need extra information about P(B) or P(B|A^c).
_Source: NCERT Class 12 Mathematics, Ch 13 "Probability", §13.3_
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