The markup on a box of apples is 10 percent of the cost. The markup is what percent of the selling price?
(markup = selling price - cost)
Choose the correct choice from the following answers:
A) 9.09 %  B) 10 %  C) 12 1 / 2 %  D) 15 %  E) 16 2 / 3 %

Rationale: mp = 0.1 cp sp = cp + 0.1 cp = 1.1 cp hence mp = 0.1 / 1.1 sp = 1 / 1 sp . hence mp is 9.09 % of sp answer a
Answer: A