Show all formulas and work

Lancaster Engineering Inc. (LEI) has the following capital structure, which it considers to be optimal
Debt	25%
Preferred Stock	15%
Common Equity	60%
	100%
Tax Rate: 40%
New capital can be obtained in the following ways:
Preferred stock with a dividend of $11.00 can be sold at $95.00 per share
Debt can be sold at an interest rate of 12% (This is the Before Tax Cost of Capital)
Cost of Equity (Answer given) = 16.26% A. Calculate the after tax cost of debt? b Calculate the cost of preferred stock? c. Calculate WACC?