b They bought equipment for $40,000.

c They hired one employee to help them for an annual wage of $18,000.

d Lisa gave up her previous job, at which she earned $22,000.

0 Bart kept his old job, which paid $20 an hour, but gave up 20 hours of leisure each week (for 50 weeks) to work for the firm.

f They bought $5,000 of goods from other Calculate the average product of labour and draw the average product curve.

b Calculate the marginal product of labour and draw the marginal product curve.