Question

If $r.v. X \sim B \left(n = 5, P=\frac{1}{3}\right)$ then $P(2 < X < 4) =$ ______________

• A. $\frac{80}{243}$
• B. $\frac{40}{243}$
• C. $\frac{40}{343}$
• D. $\frac{80}{343}$

Answer 1

Answer: (B)

$\frac{40}{243}$

Answer 2

Given, $X \sim B=\left(n=5, p=\frac{1}{3}\right)$ $\because p+q=1$ $\therefore \frac{1}{3}+q=1$ $\Rightarrow q=\frac{2}{3}$ $\therefore p(2