 conditions for consumer equilibrium. If we assume there is no budget constraint, then consumer will consume goods and services up to the quantities where marginal utility is 0. In fact, if there is no budget constraint to maximize satisfaction, consumer will use up to that quantity of the commodity where marginal utility of that commodity becomes 0. But in real life, a consumer always faces a constraint. Under given constraint, a consumer has to maximize his satisfaction. A consumer has to maximize his satisfaction keeping in mind the constraint that he is facing. To explain consumer equilibrium, we are taking apples on horizontal axis and oranges on vertical axis. In this diagram, solid blue color line, downward sloping blue color line is the budget constraint of the consumer. It indicates different combinations of apples and oranges that a consumer can afford by using his limited income. All combination of apples and oranges that lie below this blue color line are attainable combination. And all those combinations that lie above this blue color downward sloping line is unattainable under his budget constraint. As objective of the consumer is to maximize his satisfaction, under given income constraint, consumer is not in opposition to achieve a level of satisfaction that we are denoting here by using IC theory indifference curve. And similarly, there are certain combination on indifference curve IC1 that are attainable under given budget constraint but those combinations are not maximizing satisfaction of the consumer. A consumer can maximize his satisfaction under given budget constraint if it chooses a combination that lie on IC2 indifference curve. In IC2 indifference curve, he will choose that combination of commodities where slope of indifference curve and slope of budget line becomes equal. So, by choosing a combination where slope of indifference curve and slope of budget line are equal, consumer can maximize his satisfaction. Also, combination that lie on IC1, there are certain points where IC1 intersects the budget line but those combination are not indicating indicating the maximum level of satisfaction against given budget constraint. A rational consumer whenever make whenever say he is in equilibrium, he is in fact maximizing his satisfaction under given budget constraint. Mathematically, the condition of consumer equilibrium can be defined as it indicates slope of budget line is equal to slope of indifference curve. As both slope of indifference curve and slope of budget line are negative, so we are cancel out negative side from both sides of the equation. So, the first part in this equation is represents negative of the slope of the budget line. If we multiply a negative number with negative of the slope of the budget line, it will become positive number. Similarly, if we multiply a negative with negative of the slope of the indifference curve, we will get some positive number that we are noting here in the form of marginal utility of apples over marginal utility of oranges. So, to maximize satisfaction, a consumer has to equate, has to use that combination of commodities where slope of indifference curve and slope of budget line are equal. And if we make, if we rearrange this particular equation, we obtain an expression where marginal utility of oranges over price of oranges is equal to marginal utility of apples over price of apples. In this expression, when we divide marginal utility of oranges with price of oranges, it in fact reports marginal utility that a consumer is getting from each again from oranges against each rupee that he spend on oranges. Similarly, marginal utility of apples, when we divided with price of apples, it reports marginal utility drive from apples by spending by each rupee. A rational consumer can maximize his satisfaction by equating per rupee marginal utility on two commodities. If a consumer is getting satisfaction by using n commodities, then in that case, he will make expenditure in such a way where marginal utility per rupee against each commodity will be equal. For example, if someone is spending on meat, he is getting marginal utility from meat against each rupee spent on meat, then that marginal utility should be equal to marginal utility per rupee that he is getting from some other commodity. So, from this discussion, hopefully the things are clear about equilibrium of the consumer. When we say consumer is in equilibrium, it indicates consumer is maximizing his satisfaction under given budget constraint. And a consumer is maximizing his satisfaction against budget constraint if slope of the indifference curve is equal to by choosing a combination where slope of indifference curve is equal to slope of budget line. Thank you very much.