3 B. (20 Marks) a) What will the monthly payment be if you take out a $100,000 fifteen-year mortgage at an interest rate of 1% per month? How much of the first payment is interest and how much is amortisation? b) Suppose you retire at age 70 with the life expectancy of 20 more years, and you expect to spend $55,000 a year during your retirement. How much money do you need to save by age 70 to support this consumption plan? Assume an interest rate of 7%