If Castor's demand curve is described by q  40  p and Pollux's demand curve is given by q  60  2p, then each of their demand curves will pass through the point q  20, p  20.Therefore if they are the only two consumers in a market, the market demand curve will also pass through q  20, p  20.

Market Demand

The total amount of a product or service that all consumers in a market are willing and able to buy at various prices.

Point q

Point q may refer to a specific position or location in a diagram or graph, often used in the context of mathematical or economic models.

Point p

Point p could refer to a specific point on a graph or model in economics, representing a particular state or value in the given context.