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 4 of 4.

Somu said:   9 years ago
Nice explanation @Kavitha.

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

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


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