Assume that you have purchased a new car and after your down payment, you borrowed $$20,000$ from a bank to pay for the car. Also assume that you have agreed to pay off this loan by making equal monthly payments for $5$ years. Given that the annual interest rate is $10\mathrm{.}5\%,$ how much will be the payment each month? How much will be the payment if you want to pay all the rest of the loan at once at the beginning of third year?