What is the average of all numbers between 8 and 74 which are divisible by 7?

Answer: Option C

$$\begin{array}{rl}& 14,21......70\\ & \underset{\text{Divisible by 7}}{8-------74}\\ & \text{Number of items}=\frac{\text{Lat term}-\text{First term}}{\text{Common Difference}}+1\\ & =\frac{70-14}{7}+1\\ & =9\\ & \text{Average of all number divisible by 7}\\ & \Rightarrow \frac{n}{2\times n}\left[a+l\right]\\ & \Rightarrow \frac{84}{2}\\ & \Rightarrow 2\end{array}$$