12 The table shows the production function of Cathy's Cakes. Cathy rents ovens at $100 a day each and pays $50 a day for each worker.

Labour (workers) Output (cakes per day)

Plant 1 Plant 2 Plant 3 Plant 4 1 20 40 55 65 2 40 60 75 85 3 65 75 90 100 4 65 85 100 110 Ovens (number) 1 2 3 4