SSC CGL 23 Aug 2021 Shift 1 Paper

Let Radha's income is ₹100,
Saving $=100\times \frac{\mathit{x}}{100}=\mathit{x}$
Expenditure $=100-\mathit{x}$
Income after $28\%$ increase
$=100\times \frac{128}{100}=\mathit{₹}128$
Expenditure increase by $20\%$
$=\left(100-\mathit{x}\right)\times \frac{120}{100}=\left(100-\mathit{x}\right)\frac{6}{5}$
New saving $=128-\left(100-\mathit{x}\right)\frac{6}{5}$ . . . (i)
Saving increase by $40\%$
$=\mathit{x}\times \frac{140}{100}=\frac{7}{5}\mathit{x}$ . . . (ii)
From Eqs. (i) and (ii),
$\Rightarrow \left[128-\left(100-\mathit{x}\right)\frac{6}{5}\right]=\frac{7}{5}\mathit{x}$
$\Rightarrow 128-100\times \frac{6}{5}+\frac{6}{5}\mathit{x}=\frac{7}{5}\mathit{x}$
$\Rightarrow 128-120=\frac{7}{5}\mathit{x}-\frac{6}{5}\mathit{x}=\frac{1}{5}\mathit{x}$
$\Rightarrow 8=\frac{1}{5}\mathit{x}$
$\Rightarrow \mathit{x}=40$