In January, Frank bough a used car for $7200 and agreed to pay for it as follows: 1/3 down payment; the balance to be paid in 36 equal payments; the first payment due February 1st; at annual interest rate of 24%, compounded monthly. a) What is the amount of Frank's monthly payment? b) During the summer, Frank made enough money to pay off the entire balance due on car as of October 1. How did Frank owe on October 1?