Question : South African cricket captain lost the loss of coin 13 times out of 14. The chance of this happening was

(A) \dfrac{7}{2^{13}}

(B) \dfrac{1}{2^{13}}

(C) \dfrac{13}{2^{14}}

(D) \dfrac{13}{2^{11}}

Answer : option (A)

Solution :

L and W can be filled in 14 places in 2^{14} ways

therefore, n\left( s\right) =2^{14}

now 13 L’s 1 W can be arranged at 4 places in 14 ways, hence n(A) = 14.

therefore, P\left( A\right) =\dfrac{n\left( A\right) }{n\left( S\right) }=\dfrac{14}{2^{14}}=\dfrac{7}{2^{13}}.

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