If the loss of percent on article is 15%. Then the ratio of the cost price and selling price will be = ?

Answer: Option B

The loss of percent on article is 15%
$$\begin{array}{rl}& 15\%=\frac{15}{100}=\frac{3\to \text{Loss}}{20\to \text{C}\text{.P}\text{.}}\\ & \text{Selling price }=17\\ & \text{C}\text{.P}\text{.}:\text{S}\text{.P}\text{.}=20:17\end{array}$$