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) = ^{n}C_{n-1} p^{n-1} q^{1}

Since p=q

p(x=n-1)= n p^{n-1}q

=n p^{n-1}p

=np^{n}

=n

comparing LHS anr RHS

we have,

n=12

1