SSC CGL 16 Aug 2015 Shift 2 Paper

Let the C.P. of article be Rs. 100 and the marked price be Rs. x.
Case I
$\frac{\mathit{x}\times 90}{100}$ = 120
⇒ x = $\frac{120\times 100}{90}$
= Rs. $\frac{400}{3}$
Case II
S.P. = $\frac{\mathit{x}\times 80}{100}$ = Rs. $\frac{4\mathit{x}}{5}$
= Rs. $\left(\frac{4}{5}\times \frac{400}{3}\right)$ = Rs. $\frac{320}{3}$
∴ Profit = Rs. $\left(\frac{320}{3}-100\right)$
= Rs. $\left(\frac{320-300}{3}\right)$ = Rs. $\frac{20}{3}$
∴ Profit percent = $\frac{20}{3}$ %
= 6 $\frac{2}{3}$ %