Let's take a look at Invisible Hand Property 2 in action using a mathematical example. Suppose an industry is characterized by the following equations. We're going to assume that all individual rms are identical to make this problem a little simpler. 0 Demand: QD = 100 2P 0 Individual rm's supply: qS = 0.5 + 0.11\" 0 Market supply with n rms: Q; = n X 915 = 0.51/1 + 0.1nP 24.2 0 Individual rm's average cost: AC = in 5 + 49 c. The Elimination Principle says that prots will be eliminated in the long run, which means that AC 2 P. We will use that fact to gure out how many rms will be in this industry in the long run. Using AC 2 P, nd (15, the number of units that each rm IFS- Then use (Is to nd P, the longrun price of output. Now use P to nd Q Q, the amount of output demanded by consumers in the long run. Finally, use Q3 and q; to nd It, the number of rms in the long run