compard with perfect competition and monopoly

Perfect competition does not exist. THe closest example is the stock market, but still, there isnt perfect information in the transactions. So we can't compare...and even if we have such an example, the amount of profits made can differ in different circumstances and it can be affected by factors like demand and supply. So we can never compare things in such a way. We can compare the change in total revenue made in a good though, as a result of a change in the demand, the supply, or both. These types of questions always appear in CE

現實無perfect competition ,所依無得比較