Dana intends to invest $30,000 in either a Treasury bond or a corporate bond. The Treasury bond yields 5 percent before tax and the corporate bond yields 6 percent before tax. Assuming Dana’s federal marginal rate is 25 percent and her marginal state rate is 5 percent, which of the two options should she choose? If she were to move to another state where her marginal state rate would be 10 percent, would her choice be any different? Assume that Dana itemizes deductions.

Suppose that a paving company produces paved parking spaces (q) using a fixed quantity of land (t) and variable quantities of cement (c) and labor (l). the firm is currently paving 1,000 parking spaces. the firm's cost of cement is $3 comma 600.003,600.00 per acre covered (c) and its cost of labor is $35.0035.00/hour (w). for the quantities of c and l that the firm has chosen, mp subscript upper c baseline equals 60mpc=60 and mp subscript upper l baseline equals 7mpl=7. is this firm minimizing its cost of producing parking spaces?