by selling 10 pencils for a rupee a man loses 15 % . how many for a rupee should he sell in order to gain 15 % ?
85 % - - - 10 115 % - - - ? 85 / 115 * 10 = 7.39 answer : c
multiply(divide(const_1, multiply(add(const_100, 15), divide(const_1, subtract(const_100, 15)))), 10)