A shopkeeper marks his goods 20% above his cost price and gives 15% discount on the marked price. His gain percent is = ?

Let the cost price = Rs. 100
$$\eqalign{ & {\text{Market price }} \cr & {\text{ = 120}}\% {\text{ of 100 }} \cr & {\text{ = Rs}}{\text{. 120}} \cr & {\text{Selling price }} \cr & {\text{ = 85}}\% {\text{ of 120 }} \cr & {\text{ = }}\frac{{85}}{{100}} \times {\text{120 }} \cr & {\text{ = Rs}}{\text{. 102}} \cr & {\text{Gain }}\% = \frac{{102 - 100}}{{100}} \times 100 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 2\% \cr} $$