An industry has a supply curve MC (or P) $/unit = 10Q0.9. Demand follows P $/unit = 100 - Q1.1. Total external social cost (pollution) (in $ total) = 20Q1.2.
What is the competitive equilibrium? What is the resulting profit, consumer surplus, and external cost?
(You can calculate the intercept of supply + demand curves, or maximize consumer surplus + profit = integral of demand curve - integral of supply curve). Draw the supply and demand curves, and the areas corresponding to consumer surplus, profit, and external cost under this solution.