Suppose that in addition to repairing your car, you can also spend money advertising. If you repair your car for H hours and spend A dollars advertising, your benefit (the amount you receive when you sell your car) is B(H, A) = 220H -H2 + 2A. Both H and Aare finely divisible. What is your marginal benefit of repair hours when H =4 and A = 100? What is your marginal benefit of advertising dollars at that choice?