Problem:

Rollins Corporation is estimating its WACC. It's current and target capital structure is 20 percent debt, 20 percent preferred stock, and 60 percent common equity. Its bonds have a 12 percent coupon rate, paid semiannually, a current maturity of 20 years, and sell for $1,040. The firm could sell, at par, $100 preferred stock which pays a $12.00 annual preferred dividend. Rollins' common stock beta is 1.2, and the risk-free rate is 10 percent. Rollins is a constant-growth firm which just paid a dividend of $2.00. Its stock sells for $27.00 per share, and has a growth rate of 3 percent. The floatation cost is 5% for debt, 10% for preferred stock, and 25% for common stock. The firm's marginal tax rate is 40 percent.

Required:

Question: Calculate the cost of existing debt and the cost of new debt.

Note: Please provide equation and explain comprehensively and give step by step solution.