In order to supplement daily diet, a person wishes to take X and Y tablets. The contents (in milligrams per tablet) of iron, calcium and vitamins in X and Y are given as below : Tablets Iron Calcium Vitamin X 6 3 2 Y 2 3 4   The person needs to supplement at least 18 milligrams of iron, 21 milligrams of calcium and 16 milligrams of vitamins. The price of each tablet of X and Y is Rs. 2 and Rs. 1 respectively. How many tablets of each type should the person take in order to satisfy the above requirement at the minimum cost ? Make an LPP and solve graphically.