Question

(i) The sum of the first 16 odd numbers is ___
(ii) The sum of the first 25 odd numbers is ___.

Answer 1

(i) The sum of first n odd numbers = $n^2$
Ex: $1+3+5=3^2=9$
$1+3+5+7=4^2=16$
Similarly,
$1+3+5+7+.........+({16}^{th}\text{odd no}.)={16}^2=256$

(ii) The sum of first n odd numbers = $n^2$
Ex: $1+3+5=3^2=9$
$1+3+5+7=4^2=16$
Similarly,
$1+3+5+7+.........+({25}^{th}\text{odd no}.)={25}^2=625$