Question

The average of first 'n' natural numbers is

Answer 1

$Average=\frac{1+2+3+......+n}{n}\\\\Average=\frac{[(n)(n+1)]/2}{n}\\\\Average=\frac{n(n+1)}{2n}$

Sum of first natural numbers is [n (n + 1)] / 2 .

Hence, in second step (n(n+1)) / 2 is placed.