Question

Suppose X is a binomial variable B (5, p) and P(X =2) = P (X = 3), then p is equal to

• A. $\frac{1}{2}$
• B. $\frac{1}{3}$
• C. $\frac{1}{4}$
• D. $\frac{1}{5}$

Answer 1

The correct option is A $\frac{1}{2}$

Since, P(X = 2) = P(x = 3), we get
${}^5{C}_2{p}^2{q}^3{=}^5{C}_3{p}^3{q}^2\therefore q=p(\therefore q=1-q)1-p=p\therefore p=\frac{1}{2}$