1- Why would one be unable to associate particular amounts of calendar time with the concepts of market period, short-run period, long-run period and historical period ?

2- List as many reasons as you can why the low of diminishing retunes or variable proportions is likely to take effect in the short run in the operation of a business?

3- Why does marginal cost have such a strong influence on the supply response of a firm?

4- Can you think of any firms (or industries) in which long-run average cost is likely to (a) fall? (b) remain constant? (c) rise as output increases ?

5- Alpha Lumber Co. has the following short-run total costs :

Total explicit cost = $40,000

Total implicit cost = $20,000

How profitable (Economic profit, normal profit or economic loss) is the company in each of the following cases:

a- Total revenue = $65,000

b- Total revenue = $60,000

c- Total revenue = $55,000