Plant 1 Output 10 20 30 40 50 Plant 2 ATC $10 9 8 9 10 Plant 3 Output 10. 20 30 40 50 ATC $15 10 7 10 14 up to 10 units of output, and diseconomies of scale after that. B up to 20 units of output, and diseconomies of scale after that. up to 30 units of output, and diseconomies of scale after that. Output up to 40 units of output, and diseconomies of scale after that. 10 20 If the three plant sizes shown are the only ones possible, then there are economies of scale in producing 30 40 50 ATC $20 15 10 8 9