Question

The arithmetic mean of the first $n$ natural number is

• A. $\frac{(n+1)}{2}$
• B. $\frac{(n-1)}{2}$
• C. $\frac{n}{2}$
• D. None of these

Answer 1

The correct option is A $\frac{(n+1)}{2}$

The arithmetic mean of first n natural number i.e. $1,2,3,....,n$
$=\frac{1+2+3+...+n}{n}=\frac{n(n+1)}{2n}=\frac{n+1}{2}$