Question

Find the sum of all positive integers from 5 to 1555 inclusive, that are divisible by 5.

Answer 1

steps below

Explanation:

Sum = n * (a₁ + aₙ) / 2

n = 1555-5+1 = 1551

Sum = 1551*((5+1555)/2)

= 1209780

= 5 * 241956