Consider a two$-$country world, Zambia and DRC$.$ Each country has an upward$-$sloping national supply curve for soyabeans and a downward$-$sloping national demand curve for soyabeans. With no trade in soyabean, the no$-$trade equilibrium price for soyabeans in Zambia would be $$2\mathrm{.}00$ per kilogram and the no$-$trade equilibrium price for soyabeans in the DRC would be $$3\mathrm{.}20$ per kilogram. If the countries allow free trade in soyabeans, explain why $$3\mathrm{.}50$ per kilogram cannot be the free$-$trade equilibrium world price for soyabeans. In your answer, draw and refer to graphs of supply and demand curves for the two national markets.