Delta Corporation has the following capital structure:

	Cost (aftertax)			Weights			Weighted Cost
Debt (Kd)		10.6	%		15	%		1.59	%
Preferred stock (Kp)		9.8			25			2.45
Common equity (Ke) (retained earnings)		8.2			60			4.92
Weighted average cost of capital (Ka)								8.96	%

a. If the firm has $51 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 10.6 percent cost of debt referred to earlier applies only to the first $18 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").)