Question

The average of all two digit numbers that are divisible by 5 is ______.

• A. 33.5
• B. 55.5
• C. 52.5
• D. 40.5

Hint:

For an AP, the average equals (first term + last term) divided by 2.

Answer 1

The Correct Option is C

Number of terms $n = \frac{95-10}{5}+1 = 18$.
Sum of terms $= \frac{n}{2}(first+last) = \frac{18}{2}(10+95) = 9 \times 105 = 945$.
Average $= \frac{945}{18} = 52.5$.
\[\boxed{52.5}\]