on a purchase of $ 112 , a store offered a payment plan consisting of a $ 12 down payment and 12 monthly payments of $ 10 each . what percent of the purchase price , to the nearest tenth of a percent , did the customer pay in interest by using this plan ?
"12 * 10 + 12 = 132 ( 12 / 112 ) * 100 = 10.7 answer : a"
multiply(divide(subtract(add(multiply(10, 12), 12), multiply(10, 12)), 112), const_100)