SSC CHSL 19 Mar 2020 Shift 3 Paper

Let the length and breadth of the rectangular field be $/$ and $\mathit{b}$ respectively.
∴ Area of the rectangular field $=\mathrm{I}\times \mathit{b}$
After $10\%$ increase in length and breadth both, area of the rectangular field
$=\frac{110}{100}\mathrm{l}\times \frac{110}{100}\mathit{b}=\frac{121}{100}\mathrm{lb}$
∴ Percentage increase in area
$=\frac{\left(\frac{121\mathrm{lb}}{100}-\mathrm{lb}\right)}{\mathrm{lb}}\times 100=21\%$