The ratio between the sale price and the cost price of an article is 12:7. What is the ratio between the profit and the cost price of that article?	Choose the correct choice from the following:
A) 2 : 9
B) 2 : 5
C) 3 : 6
D) 5 : 7
E) 2 : 1

Rationale: "let c . p . = rs . 7 x and s . p . = rs . 12 x . then , gain = rs . 5 x required ratio = 5 x : 7 x = 5 : 7 answer : d"
Answer: D