A man buy a book in Rs50 & sale it Rs60. What is the rate of profit ??? Choose the correct choice from the following options.
A) 10 % B) 20 % C) 30 % D) 25 % E) 28 %

Rationale: "cp = 50 sp = 60 profit = 60 - 50 = 10 % = 10 / 50 * 100 = 20 % answer : b"
Answer: B