Charging 30% above its production cost a radio maker puts a label of Rs. 286 on a radio as is price. But at the time of selling it, he allows 10% discount on the labelled price. What will his gain be ?

$$\eqalign{ & {\text{Cost of ratio}} \cr & = \frac{{286}}{{130}} \times 100 \cr & = {\text{Rs}}{\text{. 220}} \cr & {\text{Selling price of ratio}} \cr & = 286 \times \frac{{90}}{{100}} \cr & = {\text{Rs 257}}{\text{.40}} \cr & {\text{Profit}} = 257.40 - 220 \cr & = {\text{Rs 37}}{\text{.40}} \cr} $$