Mark the correct alternative in the following:

Suppose a random variable X follows the binomial distribution with parameters n and p, where 0 < p < 1. If is independent of n and r, then p equals.

Given:

P=?

P(x=r)= ^{n}C_{r} p^{r} q^{n-r}

=

P(x=n-r)= ^{n}C_{n-r} p^{n-r} q^{n-(n-r)}

= ^{n}C_{r} p^{n-r} q^{r}

=

Put values in equation, we have:

1-p=p

1=2p

P=1/2

1