Hi Tutor

When a profit-maximising firm is at its short run optimum...

1. the average cost of the product is at its lowest possible point, whether a profit is being made or not
2. the firm will be shut down if its price is less than the average fixed cost
3. the profit per unit of output will be at its maximum possible level
4. none of the above will be true

and then, Which statement is true regarding firms in the long run?

1. firms can be of many different sizes if the long-run supply curve is horizontal
2. if economics of scale and diseconomies of scale exist, firms will be of the same size
3. no firms will be making economic profits
4. all of the above