Suppose both Smith and Jones utility functions of U(X,Y) = XY1/2. Smith is endowed with (X, Y) = (9,25) and Jones is endowed with (X, Y) = (25,9).
Draw an Edgeworth box with indifference curves through this endowment.
At what combinations of X and Y are both better off (i.e., are Pareto Improving)?
At what combinations of X and Y are there no more gains from trade (i.e., are Pareto Efficient)?
If they agreed on a price of one X for one Y, would they be better off?