SSC CGL 24 Aug 2021 Shift 3 Paper

Let the loss be $\mathit{₹}\mathit{y}$ when shopkeeper sold article at ₹ 455 .
If he sold at ₹ 490 he gain 4 times the loss means 4y profit.
According to the question,

$\mathit{y}=\frac{\left(\mathit{C}\mathit{P}-455\right)}{\mathit{C}\mathit{P}}\times 100$ . . . (i)

$4\mathit{y}=\frac{490-\mathit{C}\mathit{P}}{\mathit{C}\mathit{P}}\times 100$ . . . (ii)
Put $\mathit{y}$ value from Eq. (i) in Eq. (ii),
$\Rightarrow 4\times \frac{\left(\mathit{C}\mathit{P}-455\right)}{\mathit{C}\mathit{P}}\times 100$
$=\frac{\left(490-\mathit{C}\mathit{P}\right)}{\mathit{C}\mathit{P}}\times 100$
$\Rightarrow 4\mathit{C}\mathit{P}-1820=490-\mathit{C}\mathit{P}$
$\Rightarrow 5\mathit{C}\mathit{P}=1820+490=2310$
$\mathit{C}\mathit{P}=\mathit{₹}462$
If he sell at $25\%$ profit

$=462\times \frac{125}{100}=\mathit{₹}577.5$