Your classmate tells you the details of the great deal he got on his mortgage: 30-year 1.1% fixed rate with a 20% down payment it his new home costs $136,000, what is his down payment? 1 How much is he going to borrow to buy the house (assuming he only has the money to make the down payment from the previous part)? Use Excel's PMT function to determine how much his monthly payments would be. How much will he pay in interest over the lifetime of this mortgage