An investor has two bonds in his portfolio that have a face value of $1000 and pay a 10% annual coupon. Bond A matures 20 years and Bond B matures in 5 years. a) Estimate the value of each bond if the required return is 9% b)Estimate the value of each bond of the required return is 11%. (Please explain the answer in detail, do not provide answer in excel and pls attach all the formulas used clearly)