3.4

A public good that would benefit Adam, Ben and Carl has a one off cost of $388. Adam attached a value of $43.6 to this public good, for Ben its value is $404.7, and Carl values it at $121.3. The total surplus to the group if they provide the public good is:

3.8

A market is at long-run equilibrium of P* = $290 and Q* = 155100 units. All firms in the market are identical, and each has a marginal cost curve of P = 8 + 2q, where q is the quantity produced by that firm only. How many firms exist in the market?

4.2

Consider the graph below, which represents an economy closed to international trade. Given that A = 129, B = 180.6, C' = 283.8, C'' =232.2, Z = 77.4 and that the world price is $180.6, how much is the consumer surplus?