Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 53)
53.
(112 + 122 + 132 + ... + 202) = ?
385
2485
2870
3255
Answer: Option
Explanation:

(112 + 122 + 132 + ... + 202) = (12 + 22 + 32 + ... + 202) - (12 + 22 + 32 + ... + 102)

Ref: (12 + 22 + 32 + ... + n2) = 1 n(n + 1)(2n + 1)    
6

20 x 21 x 41 - 10 x 11 x 21
6 6

= (2870 - 385)

= 2485.

Discussion:
33 comments Page 2 of 4.

Atharva said:   8 years ago
Thanks, I got it.

Md. Saifuzzaman said:   8 years ago
Thank you @Majitha.

Beedisha said:   8 years ago
Why we are subtracting 1 to 10 square values?

Himansu mohanta said:   7 years ago
What is the value of n here, & how we know?

Venkat said:   7 years ago
I can't understand. Please help me to get it.

Nithish said:   7 years ago
How did ^66 Came? I didn't understand.

Ruchita said:   6 years ago
Can anyone explain me formula?

I don't want to remember it but I want to understand it.

I want to understand formula like why we have to divide 6 in this formula?

Sara said:   1 decade ago
I can't understand. Can anyone explain?

Sumedha said:   9 years ago
I didn't get a proper answer. Please, can anybody give me proper answer & shortcut.

Somu said:   9 years ago
Nice explanation @Kavitha.


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