A) 1 math problem. B) 2 math problems. C) D) 3 math problems 4 math problems. 9. A firm can use 5 workers and 10 machines, 7 workers and 9 machines, or 8 workers and 9 machines to produce 40 chairs per day. If each worker costs $400 a day and each machine can be rented for $100 a day, the economically efficient input combination is: A) 5 workers and 10 machines. B) 7 workers and 9 machines. C) 8 workers and 9 machines. D) none of these input combinations would be efficient. 10. A sporting goods store observes that as they reduce the price of squash balls from $8 to They correctly calculate elasticity $4, their quantity demanded rises from 200 to 220. of demand of squash balls to be: A) 0.14. B) 0.3. C) 3.3. D) 5. Page 2