this company sells its pants in a perfectly competitive product market at a price of $30 each and hire labor in a perfectly competitive labor market at a wage of $400 per day. find the marginal product (mpl) for the 3rd, 4th and 5th worker. (3 points) find the value of marginal product (vmpl) of the 3rd, 4th and 5th worker. (3 points) how many workers should the firm hire? how do you know? (4 points)