A die is thrown 4 times and getting 3 is considered a success. The probability of 2 successes is: |
$\frac{25}{1296}$ $\frac{1250}{72}$ $\frac{25}{216}$ $\frac{25}{72}$ |
$\frac{25}{216}$ |
The correct answer is Option (3) → $\frac{25}{216}$ $n=4,\;p=\frac{1}{6},\;q=\frac{5}{6}.$ $P(X=2)=\frac{4!}{2!(4-2)!}\left(\frac{1}{6}\right)^2\left(\frac{5}{6}\right)^2.$ $=\frac{4!}{2!2!}\cdot\frac{1}{36}\cdot\frac{25}{36}.$ $=6\cdot\frac{25}{1296}.$ $=\frac{150}{1296}.$ $=\frac{25}{216}.$ $P(X=2)=\frac{25}{216}.$ |