D 19 16 If the marginal cost is $50, average total costs are $60 and average variable costs are $40 then we know that average variable costs are falling while average total costs are rising. both average variable costs and average total costs are falling. average variable costs are rising while average total costs are falling. both average variable costs and average total costs are rising. D 10] Ra 17 19) In economics we often assume in the long-run O all costs are zero O all costs are variable some costs are fixed and some are variable O all costs are fixed D 10] 18 19 If a company has a 1-year lease on office space then this is a fixed cost in the long-run but a variable cost in the short-run. fixed cost in both the short-run and the long-run. variable cost in both the short-run and the long-run. O fixed cost in the short-run but a variable cost in the long-run. D 10 2 19 Which of the following describes a key difference between the short-run and long-run in economics? In the short-run some costs are fixed while in the long run all costs are variable. In the short-run costs are always larger than they are in the long-run. In the short-run costs are always smaller than they are in the short-run. In the short-run some costs are variable while in the long-run all costs are fixed. D 10 20 Which of the following is consistent with constant returns to scale? increasing the capacity of a factory and the average total costs decrease. increasing the capacity of a factory and the average total costs stay the same. increasing the capacity of a factory and the average total costs increase. decreasing the capacity of a factory and the average total costs increase