jmc

Question

The sales tax rate in Rubenenkoville is 6%. During a sale at the Bergville Coat Closet, the price of a coat is discounted 20% from its 90.00 price. Two clerks, Jack and Jill, calculate the bill independently. Jack rings up 90.00 and adds 6% sales tax, then subtracts 20% from this total. Jill rings up $90.00, subtracts 20% of the price, then adds 6% of the discounted price for sales tax. What is Jack's total minus Jill's total?

Accepted Answer

The price Jack rings up is (90.00)(1.06)(0.80). The price Jill rings up is (90.00)(0.80)(1.06). By the commutative property of multiplication, these quantities are the same, and the difference is 0. Reminder: Commutative states abc = bac= acb =..... and is the same in any order. This only works for addition and multiplication.