A dietician prescribes a special dietary plan using two different foods. Each ounce of food X contains 200 milligrams of calcium, 3 milligrams of iron, and 100 milligrams of magnesium. Each ounce of food Y contains 150 milligrams of calcium, 2milligrams of iron, and 80milligrams of magnesium. The minimum daily requirements of the diet are 800milligrams of calcium, 10milligrams of iron, and 200milligrams of magnesium.
a) Write and graph a system of inequalities that describes the different amounts of food X and food Y that can be prescribed.
(b) Find two solutions to the system and interpret their meanings in the context of the problem.