Consider four types of markets: monopoly, perfect competition, oligopoly, and monopolistic competition. If they were ranked from the lowest number of firms to the largest number of firms the ranking would

Monopoly

Oligopoly

monopolistic competition

Perfect competition

Explanation:

A perfect competition is characterized by many buyers and sellers of homogenous goods and services. Market prices are set by the forces of demand and supply. There are no barriers to entry or exit of firms into the industry.    

A monopolistic competition is when there are many firms selling differentiated products in an industry. A monopolistic competition has characteristics of both a monopoly and a perfect competition. the demand curve is downward sloping. it sets the price for its goods and services.

examples of monopolistic competition are restaurants  

A monopoly is when there is only one firm operating in an industry. there is usually high barriers to entry of firms. the demand curve is downward sloping. it sets the price for its goods and services.

An example of a monopoly is an utility company

An oligopoly is when there are few large firms operating in an industry. there is high barriers to entry and exit of firms

i would say their habit of breaking down.