The average of all numbers between 6 and 50 which are divisible by 5

Numbers divisible by $5$ between $6$ and $50$ are:

$10, 15, 20, 25, 30, 35, 40, 45$

These are in A.P.

Average $= \frac{\text{First term}+\text{Last term}}{2}$

$= \frac{10+45}{2}$

$= \frac{55}{2}$

$= 27.5$

Correct Answer: 27.5