The ratio between the sale price and the cost price of an article is 7:5. What is the ratio between the profit and the cost price of that article?

A. 2:7
B. 5:2
C. 7:2
D. Data inadequate
E. None of these
Explanation:
Let C.P. = Rs. 5x and S.P. = Rs. 7x.
Then, Gain = Rs. 2x
Required ratio = 2x : 5x = 2:5