By selling 12 kg of potatoes for 63, a shopkeeper gains 5%. What does his gain or loss percent by selling. 50 kg of the same potatoes for 247.50 ?

Explanation:-

Selling price of 1 potatoes $$\eqalign{ & = {\text{Rs}}{\text{.}}\frac{{63}}{{12}} \cr & = {\text{Rs}}{\text{.}}\frac{{21}}{4} \cr & {\text{CP}} \times \frac{{\left( {100 + {\text{P}}} \right)}}{{100}} = {\text{SP}} \cr & {\text{CP}} \times \frac{{105}}{{100}} = \frac{{21}}{4}{\text{ }} \cr & {\text{CP}} = {\text{Rs}}{\text{. 5}} \cr}$$ Gain or loss percent by selling 50 kg of the same potatoes for Rs. 247.50
Cost price of 50 kg potatoes
= 50 × 5
= Rs. 250
Loss = 250 - 247.50 = Rs. 2.50 $$\eqalign{ & {\text{Loss }}\% = \frac{{2.50}}{{250}} \times 100 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 1\% \cr}$$