Great Lakes Packing has two bond issues outstanding. The first issue has a coupon rate of 3.40 percent, a par value of $1,000 per bond, matures in 3 years, has a total face value of $3.1 million, and is quoted at 104 percent of face value. The second issue has a coupon rate of 5.52 percent, a par value of $2,000 per bond, matures in 16 years, has a total face value of $7.4 million, and is quoted at 97 percent of face value. Both bonds pay interest semiannually. The company's tax rate is 35 percent. What is the firm's weighted average aftertax cost of debt?

Could you explain and show the steps/formulas? I do not understand how to get the results. Can I also use a TMV solver for this problem?

Thank you for your help