Williamson, Inc., has a debtequity ratio of 2.45. The company's weighted average cost of capital is 10 percent, and its pretax cost of debt is 6 percent. The corporate tax rate is 35 percent.

a. What is the company's cost of equity capital?

b. What is the company's unlevered cost of equity capital?

c. What would the company's weighted average cost of capital be if the company's debt-equity ratio were .80 and 1.70?