2. (a) A farmer decides that each cow should get at least 15, 20 and 24 units respectively of nutrients P, Q and R daily. Two varieties of feeds are available. In feed of variety 1(variety 2), the contents of nutrients A, B and C are 1(3), 2(2) and 3(2) units per kilogram. The cost of variety 1 and 2 are respectively Ksh.2 and Ksh.3 per kg. Formulate an LP and solve it graphically to enable the manager to determine how much feed of each variety he should purchase to feed a cow daily so that the expenditure is minimized.