The ratio of the cost price and selling price is 4:5. The profit percent is?  Choose the correct answer:	A) 20 %	B) 25 %	C) 30 %	D) 50 %	E) 15 %

Rationale: "let the c . p . = $ 4 x then s . p . = $ 5 x then , gain = 5 x - 4 x = $ x gain % = x / 4 x * 100 = 25 % answer is b"
Answer: B