Answer to Question 1
The firm should hire two workers. The marginal revenue product of the second worker is 9 (30 x 0.30), which is greater than the wage of 7 . However, the marginal revenue product of the third worker is only 6 (20 x 0.30), which is less than the wage.
Answer to Question 2
The firm should hire three workers. The marginal revenue product of the third
worker is 10 (20 x 0.50), which is greater than the wage of 9 . However, the
marginal revenue product of the fourth worker is only 8 (16 x 0.50). It would
not be profitable for the firm to hire the fourth worker and thus only three
workers would be hired.