A man buy a book in Rs50 & sale it Rs50. What is the rate of profit ??? Choose the correct choice from the following answers.
A) 10 %
B) 0 %
C) 30 %
D) 25 %
E) 28 %

Rationale: "cp = 50 sp = 50 profit = 50 - 50 = 0 % = 0 / 50 * 100 = 0 % answer : b"
Answer: B