Question

Tick (✓) the correct answer:
The selling price of an article is $\frac{6}{5}$ of the cost price. The gain per cent is
(a) 20%
(b) 25%
(c) 30%
(d) 120%

Answer 1

(a) 20%

$$\begin{gathered} \mathrm{Let}\mathrm{Rs}x\mathrm{be}\mathrm{the}\mathrm{CP}\mathrm{of}\mathrm{each}\mathrm{article}. \\ \mathrm{SP}\mathrm{of}\mathrm{an}\mathrm{article}=\mathrm{Rs}\frac{6}{5}\mathrm{x} \\ \mathrm{Now},\mathrm{gain}=\left(\mathrm{SP}-\mathrm{CP}\right) \\ =\mathrm{Rs}\left(\frac{6}{5}\mathrm{x}-\mathrm{x}\right) \\ =\mathrm{Rs}\frac{\mathrm{x}}{5} \\ \therefore \mathrm{Gain}\mathrm{percentage}=\left(\frac{\mathrm{gain}}{\mathrm{CP}}\times 100\right)\% \\ =\left(\frac{{\displaystyle \frac{\mathrm{x}}{5}}}{\mathrm{x}}\times 100\right)\% \\ =\left(\left(\frac{\mathrm{x}}{5}\times \frac{1}{\mathrm{x}}\right)\times 100\right)\% \\ =20\% \end{gathered}$$