112 + 122 + 132 + ... + 202 = ?
385
2485
2870
3255
Explanation:
(112 + 122 + 132 + ... + 202) = (12 + 22 + 32 + ... + 202) - (12 + 22 + 32 + ... + 102)
Ref: (12 + 22 + 32 + ... + n2) =$\dfrac{1}{6} n(n + 1)(2n + 1)$
= (2870 - 385)
= 2485.