Country A has 1200 units of labor and can produce two goods, manufactures and food. A producers take 1 units of labor to produce one unit of manufactures and 3 units to produce one unit of food. Country B has 2100 units of labor and takes 3 units of labor to produce one unit of manufactures and 7 units to produce one unit of food. At what price of food in terms of manufactures would A and B respectively supply manufactures? What would B export in David Ricardos world? What is the amount B could supply?