The mean of 12, 22, 32, 42, 52, 62, 72 is..

The mean of $1^{2}, 2^{2}, 3^{2}, 4^{2}, 5^{2}, 6^{2}, 7^{2}$ is. A. 10 B. 20 C. 30 D. 40 Answer: Option B Show Answer Solution(By Apex Team) $\begin{aligned}&1^2+2^2+3^2+\ldots.+n^2=\frac{n(n+1)(2n+1)}{6}\\ &\therefore1^2+2^2+3^2+\ldots.+7^2=\left(\frac{7\times8\times15}{6}\right)=140\\ &\text{…

जारी रखें पढ़ रहे हैंThe mean of 12, 22, 32, 42, 52, 62, 72 is..