What is the annual tax shield to a firm that has a capital structure consisting of $100 million of debt and $180 million of equity, if the average interest rate on debt is 9%, the return on equity is 13%, and the marginal tax rate is 40%?

The management of Graphicopy is trying to determine how much debt they should have in their capital structure. If they sell $500,000 in perpetual bonds with a 9 percent coupon, what would be the present value of the tax shield? Assume the marginal tax rate is 35%.