if 1500 is increased by 20 % , and then reduced by y % , yielding 1080 , what is y ?
soln : - 1,500 * 1.2 = 1,800 . 1,800 ( 1 - y / 100 ) = 1,080 - - > ( 1 - y / 100 ) = 0.6 - - > y = 40 % . answer : b
multiply(subtract(const_1, divide(1080, multiply(1500, divide(add(const_100, 20), const_100)))), const_100)