the prices of substitutes, the cost of production, the technology used, and other factors of production, are assumed constant over the specific time period Economics () is a social science that studies the production, distribution, and consumption of goods and services. Economics focuses on the behaviour and interactions of economic agents and how economies work. Microeconomics analyses what is viewed as the basic elements of economies, including individual agents and markets, their interactions, and the outcomes of those interactions. Individual age Prices and quantities have been described as the most directly observable attributes of goods produced and exchanged in a market economy. The theory of supply and demand is an organizing principle for explaining how prices coordinate the amounts produced and consumed. In microeconomics, it applies to price and output determination for a market with perfect competition, which includes the condition of no buyers or sellers large enough to have price-setting power. For a given market of a commodity, demand is the relation of the quantity that all buyers would be prepared to purchase at each unit price of the good. Demand is often represented by a table or a graph showing the relationship between price and quantity demanded (as in the figure). Demand theory describes individual consumers as rationally choosing the most preferred quantity of each good, given income, prices, tastes, etc. A term for this is "constrained utility maximisation" (with income and wealth as the constraints on demand). Here, utility refers to the hypothesised relation of each consumer for ranking different commodity bundles as more or less preferred. The law of demand states that, in general, price and quantity demanded in a given market are inversely related. That is, the higher the price of a product, the less of it people would be prepared to buy (other things unchanged). As the price of a commodity falls, consumers move toward it from relatively more expensive goods (the substitution effect). In addition, the price decline increases purchasing power, thereby increasing the ability to buy (the income effect). Other factors can change demand; for example, an increase in income will shift the demand curve for a normal good outward, as shown in the figure. All determinants are treated as constant factors in demand and supply. Supply is the relation between the price of a good and the quantity available for sale at that price. It may be represented as a table or graph relating price and quantity supplied. Producers, for example, business firms, are hypothesized to be profit maximizers, meaning they attempt to produce and supply the quantity of goods that yields the highest profit. Supply is…