The mean of $1, 3, 4, 5, 7, 4$ is $m$. The numbers $3, 2, 2, 4, 3, 3, p$ have mean $m-1$ and median $q$. Then, $p+q=$

If the mean of frequency distribution is $8.1$ and $\Sigma f_i{x}_i=132+5k, \Sigma f_i=20$, then $k=$

The mean of first $n$ odd natural numbers is $\frac{n^2}{81}$, then $n=$