JAMB Economics 2011 Paper

Concept:Average total cost is the per-unit total cost of production, and it is read directly from the ATC curve at the given output level.Explanation:The diagram shows the firm’s cost curves, including the average total cost (ATC) curve.We need to find the ATC when the firm produces $20$ units of output.Locate $20$ units on the horizontal output axis of the graph.Trace a vertical line upward from the $20$-unit mark until it meets the ATC curve.From that point on the ATC curve, trace a horizontal line to the vertical cost axis.The value aligned on the cost axis is $\text{₦}15$.Therefore, the average total cost of producing $20$ units is $\text{₦}15.00$.This matches option D.Answer:D. $\text{₦}15.00$