help i need help on this hw problem

There are two industrial firms in the Connecticut River Valley.The government wants to reduce pollution to 80 units.What is the total cost of pollution reduction if the government limits each firm to 40 units of pollution?

There are two industrial firms in the Connecticut River Valley.The government wants to reduce pollution to 80units.What is the total cost of pollution reduction if the government issues each firm 40 vouchers, each voucher allowing the firm to produce one unit of pollution, and allowing the firms to trade (buy or sell) vouchers with each other?

Firm Initial Pollution Cost of Reducing Level Pollution by 1 Unit A 90 units $40 B 50 units $15