It'll be great if i could get answers and explanations asap

The Holmes Company's currently outstanding bonds have an8% coupon and a 10% yield to maturity. Holmes believes it could issue new bonds at par that would provide a similar yield to maturity. If its marginal tax rate is 40%, what is Holmes after-tax cost of debt? Pearson Motors has a target capital structure of 30% debt and70% common equity, with no preferred stock. The yield to maturity on the company's outstanding bonds is 9%, and its tax rate is 40%. Pearson' s CFO estimates that the company's WACC is 10.50%. What is Pearson's cost of common equity