Problem: if the cost price of 140 pencils is equal to the selling price of 100 pencils , the gain percent is
Rationale: "let c . p . of each pencil be re . 1 . then , c . p . of 100 pencils = rs . 100 ; s . p . of 100 pencils = rs . 140 . gain % = 40 / 100 * 100 = 40 % answer : e"
annotated_formula: divide(const_100, divide(100, subtract(140, 100)))