If a consumer receives 10 units of total utility from consuming 2 apples, what is the marginal utility of the third apple if it increases total utility to 13 units?

Marginal utility is the extra satisfaction or benefit a consumer gets from consuming one more unit of a good. In this case, the consumer gets 10 units of total utility from eating 2 apples. When they eat a third apple, their total utility rises to 13 units. To find the marginal utility of the third apple, we subtract the total utility from 2 apples (10 units) from the total utility after eating the third apple (13 units). So, the marginal utility of the third apple is 13 minus 10, which equals 3 units of utility.