Please help me solve this question! I don't have a financial calculator since it was not required for my Corporate Finance class. I need to see an equation to understand this. THANK YOU!!

Jiminy's Cricket Farm issued a 30-year, 6.3 percent semiannual bond eight years ago. The bond currently sells for 110 percent of its face value. The company's tax rate is 22 percent. a.What is the pretax cost of debt? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) b.What is the aftertax cost of debt? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) c. Which is more relevant, the pretax or the aftertax cost of debt? Jiminy's Cricket Farm issued a 30-year, 6.3 percent semiannual bond eight years ago. The bond currently sells for 110 percent of its face value. The company's tax rate is 22 percent. a.What is the pretax cost of debt? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) b.What is the aftertax cost of debt? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) c. Which is more relevant, the pretax or the aftertax cost of debt