Suppose the government

Suppose that demand curve for coal is given by Q = 80 - 2P and the supply curve is Q = 10(P-10), where Q is quantity (measured in millions of tons per year) and P is price (dollars per ton). Now suppose that the marginal external damage from coal use is $24 per ton. (Assume that this negative externality is the only market failure.) What is the market equilibrium price for coal (in $/ton)? What is the market equilibrium quantity for coal (in millions of tons/year)? What is the efficient quantity of coal (in millions of tons/year)?Suppose the government imposes a tax on coal. What tax rate (in $/ton) would result in the efficient quantity of coal