There are two factories in a small town. Both of them emit carbon dioxide into the air. Their current monthly emissions, as well as their total costs for reducing emissions in 20-ton increments, are listed in the tables below.

Factory 1 Current emissions (tons/month) 120 Total cost of reducing emissions by 20 tons/month $50 Total cost of reducing emissions by 40 tons/month $150 Total cost of reducing emissions by 60 tons/month $270 Total cost of reducing emissions by 80 tons/month $410 Total cost of reducing emissions by 100 tons/month $570 Factory 2 Current emissions (tons/month) 160 Total cost of reducing emissions by 20 tons/month $20 Total cost of reducing emissions by 40 tons/month $60 Total cost of reducing emissions by 60 tons/month $110 Total cost of reducing emissions by 80 tons/month $200 Total cost of reducing emissions by 100 tons/month $300