The law of diminishing marginal utility states that, as extra units of a product are consumed within a given period of time, total utility

The law of diminishing marginal utility states that as additional units of a product are consumed within a given period of time, the satisfaction or utility that a consumer derives from that product decreases.

Here's a step-by-step explanation:

1. The first unit of a product consumed provides a certain level of satisfaction or utility to the consumer.

2. As the consumer continues to consume more units of the same product, the additional satisfaction or utility they get from consuming each additional unit decreases. This is because the desire for the product decreases with each additional unit consumed.

3. This decrease in additional satisfaction or utility with each additional unit consumed is what is referred to as diminishing marginal utility.

4. Therefore, total utility increases at a decreasing rate with each additional unit of the product consumed.

5. Eventually, there may come a point where consuming additional units of the product may even lead to a decrease in total utility, if the consumer becomes satiated or even disgusted with the product. This is known as negative marginal utility.