Sunrise, Incorporated, is trying to determine its cost of debt. The firm has a debt issue outstanding with $25$ years to maturity that is quoted at $91$ percent of face value. The issue makes semiannual payments and has an embedded cost of $5$ percent annually.

a$.$

What is the company$$s pretax cost of debt? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$

If the tax rate is $24$ percent, what is the aftertax cost of debt