1.Assume consumers in Mexico and the US consume computers and shirts. If it costs 6 unit of labor to make a computer in Mexico and 2 units of labor to make a shirt, and it costs 1 unit of labor to make either a computer or a shirt in the United States, there is no way for trade to make both of these countries better off provided that each country has the same total labor supply (e.g. each country has 24 units of labor to "spend")