Firm A produces 30 tons of pollution and its cost of pollution reduction = $100 per ton
Firm B produces 20 tons of pollution and its cost of pollution reduction = $200 per ton
Firm C produces 20 tons of pollution, its costs of pollution reduction = $400 per ton
Gov gives firm A 15 tradeable permits, and firm B&C each 10 traceable pollution permits (each permit = allows right to 1 ton of pollution)
What is the total cost of pollution reduction?