Question

The sum of first ‘n’ even natural numbers is given by S_n = n (n + 1). Find n if S_n = 930.

Answer 1

Given:

S_n = n(n + 1)

S_n ​= 930

n(n + 1) = 930

n² + n − 930 = 0

Find two numbers whose product is −930 and sum is 1:

31 × (−30) = −930

n = −31 or n = 30

n = 30

So, the sum of the first 30 even natural numbers is 930.