please solve it step by step and with formulas.

1. XYZ Company has bonds outstanding with 7 years left before maturity. The bonds are currently selling for $800 per $1,000 face value. The interest is paid annually at a rate of 12 percent. The firm's tax rate is 40 percent. Calculate the after-tax cost of debt. 2. Calculate the after-tax cost of debt under each of the following conditions: a. Interest rate of 13%, tax rate of 0% b. Interest rate of 13%, tax rate of 20% c. Interest rate of 13%, tax rate of 35% 3. If a company has to float preferred stock and its floating cost is 2.5% and it pays 8% dividend then what would be the cost of capital