Final answer:
The tendency for a resource that has no price to be used until its marginal benefit falls to zero is referred to as marginal utility.
Step-by-step explanation:
The tendency for a resource that has no price to be used until its marginal benefit falls to zero is referred to as marginal utility. Marginal utility is the additional satisfaction or benefit that a person receives from consuming one more unit of a good or service. As more units of the resource are consumed, the marginal utility tends to decrease, eventually reaching zero.