A 6-month bank loan of $1,000.00 required the equal payments monthly. After three payments were made, the borrower decided to pay off the loan at the 4th month before he paid his monthly payment. The payoff sum of $524.03 was determined by the lender. Interest was quoted at 18 percent nominal, compounded monthly. The $1,000.00 was received on December 12, 1980. The three payments were made on January 12, February 12, and March 12, individually. No payment was made during April except for the final payoff on April 12. (a) How much should the monthly payment be? [2 marks] (b) Did the bank overcharge the borrower on the payoff, and if so, by how many dollars?