InterviewSolution
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Let A and B be the events such that P(A) = 1/2, P(B) = 7/12 and P(not A or not B) = 1/4.State whether A and B are(i) mutually exclusive(ii) independent |
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Answer» Given: A and B are the events such that P(A) = \(\frac{1}{2}\) and P(B) = \(\frac{7}{12}\) and P(not A or not B) = \(\frac{1}{4}\) To Find: (i) If A and B are mutually exclusive Since P(not A or not B) = \(\frac{1}{4}\) i.e., P\((\overline A\cup\overline B)\) = \(\frac{1}{4}\) we know that , P\((\overline A\cup\overline B)\)) = P(A ∩ B)' = 1 - P(A ∩ B) = 0 But here P(A ∩ B) \(\neq\) 0 Therefore , A and B are not mutually exclusive. (ii) If A and B are independent The condition for two events to be independent is given by P(E1 ∩ E2) = P(E1) x P(E2) = \(\frac{1}{2}\times \frac{7}{12}\) = \(\frac{7}{24}\) Equation 2 Since Equation 1 \(\neq\) Equation 2 \(\Rightarrow\) A and B are not independent |
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