Suppose Dwight and Barrack were to exchange 1 unit of the good.
1) The potential gain from trade for the first unit of the good they exchange is:
2) Suppose Dwight and Barrack were to exchange 1 unit of the good for $45. Dwight's gain from trade at that price is:
3) Suppose Dwight and Barrack were to exchange 1 unit of the good for $45. Barrack's gain from trade at that price is: