Question

Find the sum of first 100 even number which are divisible by 5.

Answer 1

The first few even natural numbers which are divisible by 5 are 10, 20, 30, 40, ...

This is an AP in which a = 10, d = (20 – 10) = 10 and n = 100 

The sum of n terms of an AP is given by

Hence, the sum of the first hundred even natural numbers which are divisible by 5 is 50500.