The arithmetic mean of first 11 natural numbers is

Answer: Option C

Required mean
$$\begin{array}{rl}& =\left(\frac{1+2+.....+11}{11}\right)\\ & =\left(\frac{1}{11}\times \frac{11\times 12}{2}\right)\\ & =6\end{array}$$
$$\left[\because 1+2+.....+n=\frac{n\left(n+1\right)}{2}\right]$$