Browse Questions

# Find the mean of first $n$ odd natural numbers.

$\begin {array} {1 1} (A)\;n & \quad (B)\;n^2 \\ (C)\;0 & \quad (D)\;n^3 \end {array}$

Ans : (A)
First $n$ odd natural numbers are $1, 3, 5....2n+1$
Mean = $\large\frac{1+3+5+...+(2n-1)}{n}$
$= \large\frac{\large\frac{n}{2}[1+(2n-1)]}{n}$
$= \large\frac{n^2}{n}$
$= n$