A dietician wishes to mix two types of foods : 'Food I' and 'Food II' in such a way that the vitamins contents of the mixture contains atleast 8 units of vitamin A and 10 units of vitamin C. Food I contains 2 units/kg of vitamin A and one unit/kg of vitamin C. It costs ₹5 per kg to purchase Food I and ₹7 per kg to purchase Food II. He wishes to minimise the cost of the mixture. If x, y are quantities of Food I, II purchased, then the objective function is :

Min z=5x + 7y

The correct answer is Option (3) → Min z = 5x + 7y

cost of purchase 1 unit of Food I = 5

1 unit of Food II = 7

quantity of food I = x

food II = y

so objective function = minimise (5x + 7y)