100 oranges are bought at the rate of Rs. 350 and sold at the rate of Rs. 48 per dozen. The percentage of profit or loss is:

$$\eqalign{ & {\text{C}}{\text{.P}}{\text{.}}\,{\text{of}}\,{\text{1}}\,{\text{orange}}\, \cr & = Rs.\,\left( {\frac{{350}}{{100}}} \right) = Rs.\,3.50 \cr & {\text{S}}{\text{.P}}{\text{.}}\,{\text{of}}\,{\text{1}}\,{\text{orange}} \cr & = Rs.\,\left( {\frac{{48}}{{12}}} \right) = Rs.\,4 \cr & \therefore {\text{Gain}}\% = \left( {\frac{{0.50}}{{3.50}} \times 100} \right)\% \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{100}}{7}\% \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 14\frac{2}{7}\% \cr} $$