Question

What is the sum of the squares of the first 20 natural numbers (1 to 20)?

Answer 1

it can be done using the formula n(n+1)(2n+1)/6
where n is the last natural number
sum = 20(20+1)(40+1)/6
         =2780



hope this helps you pls mark as best

Answer 2

squares of numbers are
1 - 1
2 - 4
3 - 9
4 - 16
5 - 25
6  - 36
7 - 49
 8 - 64
9 - 81
10 - 100
11 - 121
12 - 144
13 - 169
14 - 196
15 - 225
16 - 256
17 - 289
18 - 324
19 -361
20 -  400

sum of squares is 1+4+9+16+25+36+49+64+81+100+121+141+169+196+225+256+289+324+361+400
= 2867