Question

what is law of diminishing marginal utility?​

Answer 1

In economics, the law of diminishing marginal utility states that the marginal utility of a good or service declines as its available supply increases. Economic actors devote each successive unit of the good or service towards less and less valued ends.

Answer 2

A psychological generalization that the perceived value of, or satisfaction gained from, a good to a consumer declines with each additional unit acquired or consumed.

Even the most delicious food, for example, will appeal less and less to its consumer when he or she has had enough, and if consumption continues, sickness (disutility) will result. Consumers deal with this phenomenon by consuming a variety of goods rather than lots of one good.