The firm is financed with debt and equity. The book value of the debt is $10,000,000; the book value of the equity is $30,000,000. The stockholders require an 10.1% return. If the required return on...

The firm is financed with debt and equity. The book value of the debt is $10,000,000; the book value of the equity is $30,000,000. The stockholders require an 10.1% return.
If the required return on the firm’s debt is 4% and the firm’s tax rate is 20%, what is the firm’s weighted average cost of capital (WACC)?