A shop sells orange juice in the following ways: 250 ml bottle for £0.70 1.5 l carton for £2.40 each or 2 cartons for £4.50 2 l carton for £3.50 What's the cheapest way of buying exactly 5 litres with no extra? Find the amount of each type of bottle or carton you need and the total cost of buying 5 litres.