Bondi Panorama is a boutique motel located near Bondi Beach. For one night accommodation per person, the motel charges $50. The owner of the motel estimates that the variable cost per person is $20, which includes food and room services. The fixed cost is estimated to be $42,000 per year.

Required: Calculate

(1)The contribution margin per unit of service (the per unit of service is one night accommodation for one guest) and the contribution margin ratio (5 marks)