I must use Microsoft Excel

Problem 3. You are buying a car that costs $15,000. The bank secured a loan at 6% interest, which you have to pay off in 60 months. a. Calculate the monthly payment using the built in PMT function. b. You find the payment in part (a) to be too high. You can afford only a monthly payment of $225. How many monthly payments of $225 will you need to make until the loan is paid off? (Use Goal Seek)