Currently Warren Industries can sell 15-year, $1,000 par value bonds paying annual interest at a 12% coupon rate. As a result of current interest rates, the bonds can be sold for $1,010 each; flotation costs of $30 per bond will be incurred in this process. The firm is in the 40% tax bracket

a) Find the net proceeds from the sale of the bond,

b) Show the cash flows from the firm's point of view over the maturity of the bond

c) Calculate the before-tax and after tax costs of debt

d) Use the approximation formula to estimate the before-tax and after-tax costs of debt

e) Compare and contrast the costs of debt calculated in parts c and d. Which approach do you prefer?

I am unable to find the formulas that fit this problem