A diet is to contain at least 80 units of vitamin A and 100 units of minerals. Two foods `F_1` and `F_2` , are available. Food `F_1` costs Rs 4 per unit food and F, costs Rs 6 per unit. One unit of food `F_1`, contains 3 units of vitamin A and 4 units of minerals.One unit of food` F_2,`contains 6 units of vitamin A and 3 units of minerals.Formulate a LPP. find the minimum cost of diet which matches the minimal requirement