A seller marks his goods 30% above their cost price but allows 15% discount for cash payment. His percentage of profit when sold in cash is = ?

Answer: Option A

Let cost price of item = Rs. 100
Marked price of item = 130% of 100
$$\begin{array}{rl}& \text{ = 130}\%\text{ of 100}\\ & \text{ = }\frac{130}{100}\times \text{100 }\\ & \text{ = Rs}\text{. 130 }\end{array}$$
After discount, selling price
$$\begin{array}{rl}& \text{= 85}\%\text{ of 130 }\\ & =\frac{85}{100}\times \text{130 }\\ & \text{= Rs}\text{. 110}\text{.5}\\ & \text{Profit}\%\\ & =\frac{110.50-100}{100}\times 100\\ & =10.5\%\end{array}$$