if the cost price of 65 chocolates is equal to the selling price of 50 chocolates , the gain percent is :
"explanation : solution : let c . p . of each chocolate be re . 1 . then , c . p . of 50 chocolates = rs . 50 ; s . p . of 50 chocolates = rs . 65 . . ' . gain % = 15 * 100 / 50 = 30 % answer : d"
divide(const_100, divide(50, subtract(65, 50)))