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Mark the correct alternative in the following:
The probability of selecting a male or a female is same. If the probability that in an office of n persons (n – 1) males being selected is , the value of n is
Given:
P(females)=p(males)=1/2
p(x=n-1) =
n=?
p(x=n-1) = nCn-1 pn-1 q1
Since p=q
p(x=n-1)= n pn-1q
=n pn-1p
=npn
=n
comparing LHS anr RHS
we have,
n=12