When a consumer is at equilibrium, the MRSxy is equal to the

When a consumer is at equilibrium, the Marginal Rate of Substitution (MRS) is equal to the ratio of the two prices. The MRS is the rate at which a consumer is willing to substitute one good for another while maintaining the same level of satisfaction. It represents the slope of the indifference curve, which shows the combinations of two goods that give the consumer the same level of satisfaction. At equilibrium, the consumer maximizes their satisfaction subject to their budget constraint, and the MRS equals the ratio of the two prices. This means that the consumer is willing to trade one unit of a good for a certain number of units of another good at a rate that is equal to the ratio of the prices of the two goods. For example, if the price of good X is ?5 and the price of good Y is ?10, then the consumer will be willing to trade one unit of good Y for two units of good X, because 2 units of X cost ?10, which is the same as the cost of one unit of Y. Therefore, at equilibrium, the consumer is willing to trade the goods at a rate that is equal to the ratio of the prices of the two goods. The other options (sum of the prices, product of the two prices, difference of the two prices) are not related to the concept of MRS or consumer equilibrium.