Camberra Freight is in charge of transporting auto parts for an US car manufacturer in Australia. Every week a tractor and one or two trailers move from the port of Melbourne to a warehouse located 430 km away. A tractor costs A$ 75 per day, a trailer A$ 30 and a driver A$ 7.5/h, while running costs are A$ 0.75/km. A trailer can contain 36 pallets. Derive the transport cost per pallet as a function of shipment size for the case where one or two trailers are used.