Answer:
7.5%
Explanation:
Calculation to determine what is Holmes' after-tax cost of debt
Using this formula
After-tax cost of debt=YTM (1-Taxes)
Where,
YTM = 10%
Tax Rate = 25%
Let plug in the formula
After-tax cost of debt= 10%(1-25%)
After-tax cost of debt=10%(75%)
After-tax cost of debt=0.075*100
After-tax cost of debt=7.5%
Therefore Holmes' after-tax cost of debt is 7.5%