If the selling price of an article is doubled, then the profit becomes four times. What was the original profit percentage?

Correct option is C

Formula Used:
Profit = SP – CP
Profit % = $$\frac{ Profit}{CP}$$​ × 100
Solution:

4 × (S.P - C.P) = 2 × S.P - C.P
4S.P - 4C.P = 2S.P - C.P
2S.P = 3C.P
S.P / C.P = 3/2
Profit percentage = {(3 - 2) × 100} / 2
= 100/2
= 50%