A tradesman marks his goods 30% above the C.P. If he allows a discount of 6¹/₄ %, then his gain percent is -

Explanation:-

$$\eqalign{ & {\text{Let C}}{\text{.P}}{\text{. be Rs}}{\text{.100}}{\text{.}} \cr & {\text{Then, }} \cr & {\text{marked price = Rs}}{\text{.130}}{\text{.}} \cr & {\text{Selling Price}} \cr & {\text{ = }}\left( {100 - \frac{{25}}{4}} \right)\% {\text{ of Rs}}{\text{.130}} \cr & {\text{ = Rs}}{\text{.}}\left( {\frac{{375}}{{400}} \times 130} \right) \cr & = {\text{Rs}}{\text{.121}}{\text{.875}}{\text{.}} \cr & \therefore {\text{ Profit }}\% \cr & {\text{ = }}\left( {121.875 - 100} \right)\% \cr & {\text{ = 21}}{\text{.875}}\% \cr & {\text{ = }}\frac{{21875}}{{1000}}{\text{ }}\% \cr & {\text{ = 21}}\frac{7}{8}\% . \cr}$$