Question

The average of $6$ numbers is $9$. If $2$ is added to each number, what will be the new average?

Answer 1

$\begin{array}{c}Sumof6numbers=6\times 9=54\\ Newaverage=\frac{6\times 2+54}{6}\\ =\frac{12+54}{6}=\frac{66}{6}\\ =11\end{array}$