By selling an article for Rs. 100 a man gains Rs.15. Then, his gain % is -

Answer: Option C

$$\begin{array}{rl}& \text{S}\text{.P}\text{.}=\text{Rs}\text{. }100\\ & \text{Gain}=\text{Rs}\text{. }15.\\ & \therefore \text{C}\text{.P}\text{.}=\text{Rs}.\left(100-15\right)\\ & =\text{Rs}\text{. }85\\ & \text{Gain }\%=\left(\frac{15}{85}\times 100\right)\%\\ & =\frac{300}{17}\%\\ & =17\frac{11}{17}\%\end{array}$$