The marked price of an article is 50% more than its cost price. If 20% discount is given, then what will be the profit percentage?

Given, marked price of an article is 50% more than its cost price i.e 

MRP = 150 % of CP (or) MRP = $$\frac{3}{2}$$ of CP (or) $$\frac{MRP}{CP} = \frac{3}{2}$$

Let, MRP = 3$$x$$ and CP = 2$$x$$

If 20% discount is given MRP becomes 80% of 3$$x$$ (or) $$\frac{12}{5}x$$ (or) $$2.4x$$

Profit percentage = $$\frac{2.4x - 2x}{2x}$$ x 100

$$\Rightarrow$$ $$\frac{0.4}{2}$$ x 100 = 0.2 x 100 = 20%

Hence, option A is the correct answer.