Number of Workers	Output	Fixed Cost	Variable Cost
0	0	$30	$0
1	100	$30	$15
2	180	$30	$30
3	240	$30	$45
4	280	$30	$60
5	300	$30	$75

Refer to Table 2. What is the marginal product of the third worker?

A: 80 units

b: 60 units

c: 40 units

d: 20 units

Refer to Table 2. The average total cost of producing 240 units is

a: $0.13

b:$0.19

c:$0.32

d:$0.80

Refer to Table 2. The marginal products of hiring additional workers are
a: increasing at an increasing rate b: increasing at a decreasing rate c: decreasing d: constant