Scenario 18-1 Harry owns a snow-removal business. He hires workers to shovel driveways for him during the winter. The first worker he hires can shovel twelve driveways in one day. When Harry hires two workers, they can shovel a total of 22 driveways in one day. When Harry hires a third worker, he shovels an additional eight driveways in one day. Refer to Scenario 18-1. Suppose that Harry pays each worker $80 per day and that he charges each customer $20 to have his driveway shoveled. What is the value of the marginal product of labor for the third worker