Delta Corporation has the following capital structure:

Cost

(aftertax)WeightsWeighted

CostDebt (K_d)9.6%30%2.88%Preferred stock (K_p)7.850.39Common equity (K_e) (retained earnings)9.2655.98Weighted average cost of capital (K_a)9.25%

a.If the firm has $52 million in retained earnings, at what size capital structure will the firm run out of retained earnings?(Enter your answer in millions of dollars (e.g., $10 million should be entered as "10").)

b.The 9.6 percent cost of debt referred to earlier applies only to the first $24 million of debt. After that the cost of debt will go up. At what size capital structure will there be a change in the cost of debt?(Enter your answer in millions of dollars (e.g., $10 million should be entered as "10").)