if the cost price of 81 chocolates is equal to the selling price of 45 chocolates , the gain percent is :
"explanation : solution : let c . p . of each chocolate be re . 1 . then , c . p . of 45 chocolates = rs . 45 ; s . p . of 45 chocolates = rs . 81 . . ' . gain % = 36 * 100 / 45 = 80 % answer : a"
divide(const_100, divide(45, subtract(81, 45)))