A store has an offer 'Buy 4 Get 1 Free'. What is the net percentage of discount ?

Answer: Option C

Let, Marked price of the thing is Rs. 100

SP	Discount	MP
400	100	500

$$\begin{array}{rl}& \therefore \text{Discount}\%\\ & =\frac{100}{500}\times 100\\ & =20\%\end{array}$$