The market supply and demand functions for a good traded on a perfectly competitive market are:

Q_d=70-2P

Q_s=20+3P

What is the equilibrium price and quantity on this market? Price =______ ; Quantity =_______ ?

If the consumption of each unit of this good gives rise to a social cost of $5, what is the socially optimal equilibrium quantity and price? Assume that consumers pay a tax of $5 per unit. New price =_______ ; New quantity =________ .

If the consumption of each unit of this good gives rise to a social benefit of $10, what is the socially optimal equilibrium quantity and price? Assume that consumers receive a subsidy of $10 per unit. New price =________ ; New quantity =________ .