Question

The percentage increase in the area of a square, if its sides are made twice is

Answer 1

let the side be x
$area = {x}^{2} \\ now \: new \: side \: 2x \\ then \: area = 4 {x}^{2} \\ percentage \: increase = \frac{4 {x}^{2} - {x}^{2} }{ 4 {x}^{2} \ } \times 100 \\ \% = 75$