How can this question be solve using simplex method;

A dietician has to develop a special diet using two foods P and Q. Each packet (containing 30kg) of food P containing 12 units of calcium, 4 units of iron, 6 units of cholesterol and 6 units of vitamin A. Each packet of the sane quantity of foods Q contain 3 units of calcium, 20 units of iron, 4 units of cholesterol and 3 units of vitamin A. The diet require at least 240 units of calcium, at least 460 units of iron and at most 300 units of cholesterol. How many packet of each food should be use to minimize the amount of vitamin A in the diet. What is the minimum amount of vitamin A.