Economics - Please?

Question

When Burger King hires one worker, 20 customers can be served in an hour. When Burger King hires two workers, 50 customers can be served in an hour. The marginal product of the second worker is

15 customers

30 customers

40 customers

50 customers

Answer 1

30 customers / hour.

That's what the second worker "marginally" contributes.

Answer 2

50-20=30 Customers

Answ: The marginal product of the second worker is 30 customers

Answer 3

50 - 20 = 30

marginal product of labor is the extra output that an extra unit of labor produces for the business.

Answer 4

30 customers