You plan to purchase a $320,000 house using elther a 30-year mortgage obtained from your local savings bank with a rate of 7.25 percent, or a 15-year mortgage with a rate of 6.25 percent. You will make a down payment of 20 percent of the purchase price a. Calculate the amount of interest and, separately, principal paid on each mortgage. What is the difference in interest paid? b. Calculate your monthly payments on the two mortgages. What is the difference in the monthly payment on the two mortgages? (For all requirements, do not round intermediate calculations. Round your answers to 2 decimal places.(e.g. 32.16)) a. Interest under 15-year mortgage Interest under 30-year mortgage Difference in interest paid b. Monthly payment under 15-year mortgage Monthly payment under 30-year mortgage Difference in monthly payment