Q3 Cost Curves Rex Carr owns a junk yard. Rex can use one of two methods to destroy cars. 1. Use a hydraulic car crusher that costs $3000 plus $10 per car. 2. Buy a heavy-duty shovel that costs $300 and then paying his brother, Scoop, to bury cars at a cost of $100 per car. 3] Write down the total cost functions associated with the two different methods for wrecking cars. b] What is the average cost of each method? c) What is the marginal cost of each method? d] Which method minimizes the cost of wrecking k cars per year? [Express your answers as "if k is less than ..." and "if k is greater or equal to ..."]