A company's balance sheets show a total of $ 30 million long-term debt with a coupon rate of 12 percent. The yield to maturity on this debt is 8.25 percent, and the debt has a total current market value of $ 34 million. The balance sheets also show that that the company has 10 million shares of stock; the total of common stock and retained earnings is $30 million. The current stock price is $7.5 per share. The current return required by stockholders, r_s, is 13 percent. The company has a target capital structure of 40 percent debt and 60 percent equity. The tax rate is 40%. What weighted average cost of capital should you use to evaluate potential projects? Express your answer in percentage.