What is the sum of the squares of the digits from 1 to 9? · ABC26GN0071

Subject: General Aptitude · Chapter: Number System

What is the sum of the squares of the digits from 1 to 9?
(a)105
(b)260
(c)285
(d)385
Answer
Answer (as printed): C
Explanation
We know that: $1^{2}+2^{2}+3^{2}+\ldots+n^{2}=\frac{1}{6} n(n+1)(2 n+1)$. $\therefore\left(1^{2}+2^{2}+3^{2}+\ldots \ldots \ldots+9^{2}\right)=\left(\frac{1}{6} \times 9 \times 10 \times 19\right)=285$.

Explanation as extracted from the printed page; notation may be imperfect.

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