Question

The sum of perfect squares of first 20 natural numbers.

Answer 1

n( n+1) (2n+1) /6

20(21)(21)/6

2870

Answer 2

Step-by-step explanation:

1sq + 2sq + 3sq.........+20sq

THE SUM OF PERFECT SQAURE OF FIRST 20 NATURAL NO.

HERE, n=20

REQUIRED SUM = n(n+1) (2n+1) by 6

(20) (20+1) (2×20+1) by 6

= 20 × 21 × 41 by 6

10 × 7 × 41 = 2870