A discount of 10% is given by a salesman for cash payment. What should be the marked price if he wants to earn a profit of 5% ?

Answer: Option A

$$\begin{array}{rl}& \text{Cost price}:\text{Marked price}\\ & \left(100-\text{D}\%\right):\left(100+\text{P}\%\right)\\ & \underset{15}{\underbrace{90\text{:}\text{105}}}\end{array}$$
Percentage of marked price above cost price
$$\begin{array}{rl}& =\frac{15}{90}\times 100\\ & =16\frac{2}{3}\%\\ & =16.67\%\end{array}$$