An article was sold for Rs. y after giving a discount of x%. Then, its list price is ?

Answer: Option A

Let the list price be Rs. z.
$$\begin{array}{rl}& \therefore \left(100-x\right)\%\text{ of z}=\text{y}\\ & \Rightarrow \left(\frac{100-x}{100}\right)\times \text{z}=\text{y}\\ & \Rightarrow \text{z}=\left(\frac{100\text{y}}{100-x}\right)\end{array}$$