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Let A and B be two independent events such that P(A)=kP(A)=k, P(B)=2kP(B)=2k and probability of occurrence of exactly one of them is 59\dfrac{5}{9}. Then the value(s) of kk is/are:

Solution

✅ Correct Option: 3

For independent events, P(exactly one)=P(A)+P(B)−2P(A)P(B)=3k−4k2P(\text{exactly one}) = P(A)+P(B)-2P(A)P(B) = 3k-4k^2.

Setting 3k−4k2=593k-4k^2 = \dfrac{5}{9} gives 36k2−27k+5=036k^2-27k+5 = 0, so k=13k = \dfrac{1}{3} or k=512k = \dfrac{5}{12}.

Both satisfy 2k≤12k \le 1, so both are admissible.

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