Question

Show that $289$ is the sum of $17$ odd natural numbers. [2 marks]

Answer 1

$289={17}^2$
and we know that the sum of first $n$ odd natural numbers is $n^2$.
[1 mark]

Therefore, $289=\text{sum of first}17\text{odd natural numbers}$

$=1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33$
[1 mark]