How long will it take your money to triple if you receive 10% return on your money, compounded annually?

Granby foods' (gf) balance sheet shows a total of $25 million long-term debt with a coupon rate of 8.50%. the yield to maturity on this debt is 8.00%, and the debt has a total current market value of $27 million. the company has 10 million shares of stock, and the stock has a book value per share of $5.00. the current stock price is $20.00 per share, and stockholders' required rate of return, r s, is 12.25%. the company recently decided that its target capital structure should have 35% debt, with the balance being common equity. the tax rate is 40%. calculate waccs based on book, market, and target capital structures. what is the sum of these three waccs?