(Diet problem): A dietician wishes to mix two types of foods in such a way that vitamin contents of the mixture contain atleast 8 units of vitamin A and 10 units of vitamin C. Food I contains 2 units/kg of vitamin A and 1 unit/kg of vitamin C. Food II contains 1 unit/kg of vitamin A and 2 unite/kg of vitamin C. It costs Rs 50 per kg to purchase Food T and Rs 70 per kg to purchase Food IF. Formulate this problem as a linear programming problem to minimise the cost of such a mixture.