RRB Group D 27-Sep-2018 Shift 1 Solved Paper

Going through options,
(i) $125,$ to find squares of numbers having 5 as unit digit, first rewrite 25 .
Then place multiplication of 12 and next number i.e., $13,12\times 13=156$ before $25,$ which makes it
${\left(125\right)}^2=15625$
So, square root of 15625 will be 125 .