A shopkeeper sells a badminton racket, whose marked price is Rs. 30, at a discount of 15% and gives a shuttle cock costing Rs. 1.50 free with each racket. Even then he makes a profit of 20% . His cost price per racket is.

Explanation:-

$$\eqalign{ & {\text{Marked Price}} = {\text{Rs}}{\text{.30}}{\text{.}} \cr & {\text{Selling Price}} \cr & = {\text{Rs}}{\text{.}}\left[ {\left( {\frac{{85}}{{100}} \times 30} \right) - 1.50} \right] \cr & = {\text{Rs}}{\text{.}}\left( {25.50 - 1.50} \right) \cr & = {\text{Rs}}{\text{.2}}4. \cr & {\text{Let }}C.P.be{\text{Rs}}{\text{. }}x. \cr & {\text{Then,}} \cr & {\text{120}}\% {\text{ of }}x = {\text{24}} \cr & \Rightarrow x = \left( {\frac{{24 \times 100}}{{120}}} \right) \cr & \,\,\,\,\,\,\,\,\,\,\,\, = {\text{Rs}}{\text{. }}20. \cr}$$