Calculate the present value of the following: (a) (7 pts) A perpetuity with a face value of $100 and a coupon of 7% where the interest rate is 10% and the 1st payment is made at the end of year 1. (b) (7 pts) A perpetuity with a face value of $100 and a coupon of 7% where the interest rate is 10% and the 1st payment is made at the end of year 10 . (c) (6 pts) A 9 year annuity with a face value of $100 and a coupon of 7% where the interest rate is 9% and the 1st payment is made at the end of year 1