This a question from an "Interest Theory" course:

5. (10 points) An investor borrows an amount at an annual effective interest rate of 6.6%. He repays all interest and principal in a lump sum at the end of 15 years from now. The investor uses the amount borrowed to purchase now two bonds: a 15-year bond with a par value of 10000, redemption amount of 15000 and semiannual coupons at a nominal interest rate of 6% convertible semiannually, and a 15-year bond, redeemed at par and sold at par, with a par value of 12000 and semiannual coupons. Both bonds have the same nominal yield rate of 4% convertible semiannually. As the investor receives each coupon payment from these two bonds, he immediately deposits the money into an investment account earning an annual effective interest rate of 12.78%. Calculate the investor's accumulated value at the end of 15 years after the loan is repaid