The Rich Corporation has $150 million worth of common stock on which investors require a 15% rate of return. It has $35 million in bonds that offer a 5% return.

a.	Calculate the WACC for Rich Corporation if they are subject to a 35% tax rate.
b.	Recompute Richs' WACC assuming the firm has $95 million in debt and $90 million in stock.
c.	After reviewing parts a. and b. explain why the WACC calculated in part b. may not be the correct answer if the capital structure changes.