If the cost price of 12 pencils is equal to the selling price of 8 pencils, the gain percent is: Choose the correct choice from the following options.
A) 30
B) 40
C) 50
D) 60
E) 70

Rationale: c 50 % let c . p . of each pencil be $ 1 . then , c . p . of 8 pencils = $ 8 ; s . p . of 8 pencils = $ 12 . gain % = 4 / 8 * 100 = 50 %
Answer: C