3. Suppose the aggregate demand and supply for a good are given by the following expressions: Qd (p) = 30-p and Q (p) = p a) What is the competitive equilibrium price and quantity? b) Suppose the production of this good results in the creation of harmful pollution. To reduce the amount of pollution being created, the government decides to charge a per unit tax of 7 on each unit of the good produced. If the government wants to reduce the amount of the good being produced by 50% (i.e. they want to get output to half of the competitive equilibrium level), at what level must they set the tax t?