# The mean of a binomial distribution is $5$ and its standard deviation is $2.$ Then the value of $n$ and $p$ are
$\begin{array}{1 1}(1)\left(\frac{4}{5},25\right)&(2)\left(25,\frac{4}{5}\right)\\(3)\left(\frac{1}{5},25\right)&(4)\left(25,\frac{1}{5}\right)\end{array}$