Firms’ costs, revenue and objectives — practice question

The table presents the daily output and costs for four firms that produce chairs. Which firm has the greatest average cost of production?

• Aoutput $6$, fixed costs $100$, variable costs $140$
• Boutput $9$, fixed costs $30$, variable costs $150$
• Coutput $12$, fixed costs $200$, variable costs $160$
• Doutput $15$, fixed costs $120$, variable costs $330$