a merchant has selected two items to be placed on sale , one of which currently sells for 45 percent less than the other . if he wishes to raise the price of the cheaper item so that the two items are equally priced , by what percentage must he raise the price of the less expensive item ?
"expensive item = $ 100 ; cheap item = $ 55 ; we must increase $ 55 to $ 100 , so by $ 45 , which is approximately 80 % increase : ( 100 - 55 ) / 55 = 3 / 7 = ~ 0.81 . answer : c ."
multiply(divide(divide(45, const_100), subtract(const_1, divide(45, const_100))), const_100)