Question

A trader marks his goods at 30% above cost price and allows a discount of 10%. What is his gain per cent?

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{CP}\mathrm{be}\mathrm{Rs}100. \\ \mathrm{Then},\mathrm{marked}\mathrm{price}=\mathrm{Rs}130 \\ \mathrm{Discount}=10\%\mathrm{of}\mathrm{MP} \end{gathered}$$

$$\begin{gathered} =\left(10\%\mathrm{of}\mathrm{Rs}.130\right) \\ =\mathrm{Rs}.\left(130\times \frac{10}{100}\right) \\ =\mathrm{Rs}.13 \end{gathered}$$

$$\begin{gathered} \mathrm{Now},\mathrm{SP}=\left(\mathrm{MP}\right)-\left(\mathrm{discount}\right) \\ =\mathrm{Rs}.\left(130-13\right) \\ =\mathrm{Rs}.117 \\ \therefore \mathrm{Gain}\mathrm{percentage}=\left(117-100\right)\% \\ =17\% \end{gathered}$$
$\therefore \mathrm{The}\mathrm{gain}\mathrm{percentage}\mathrm{of}\mathrm{the}\mathrm{trader}\mathrm{is}17\%.$