What is the cost of debt after tax? PLEASE, I NEED TO KNOW THE STEP BY STEP CALCULATION AND FORMULA WITHOUT EXCEL BECAUSE I DON'T UNDERSTAND MUCH ABOUT YTM, THANKYOU

Debt: 50,000 bonds with a coupon rate of 5.7 percent and a current price quote of 106.5; the bonds have 20 years to maturity. 200,000 zero coupon bonds with a price quote of 17.5 and 30 years until maturity.

Preferred stock: 125,000 shares of 4 percent preferred stock with a current price of $79, and a par value of $100.

Common stock: 2,300,000 shares of common stock; the current price is $65, and the beta of the stock is 1.20.

Market: The corporate tax rate is 40 percent, the market risk premium is 7 percent, and the risk-free rate is 4 percent.