The cost price of an book is 64% of the marked price. Calculate the gain percent after allowing a discount of 12%?	Answers:
A) 33 %	B) 28.02 %	C) 37.5 %	D) 30.5 %	E) 22 %

Rationale: c 37.5 % let marked price = $ 100 . then , c . p . = $ 64 , s . p . = $ 88 gain % = 24 / 64 * 100 = 37.5 % .
Answer: C