Masterson Inc. has two bond issues outstanding. The first has a face value of $40 million, has a coupon rate of 4% and sells for 95% of par. The second has a face value of $80 million, has a coupon rate of 6% and sells for 105 percent of par. The first issue matures in 10 years and the second in 15 years. Both bonds make semiannual payments. The tax rate is 20%. What is Masterson's aftertax cost of debt