試題詳解

2. The marginal utility of the first cup of coffee that Tom drinks in the morning is worth $2.00. The marginal utility of the 9th cup of coffee he drinks is positive while the marginal utility of the 10th cup of coffee he drinks in the morning is worth $0. This implies that at a price of$0, Tom would drink:
(A) zero cups of coffee per morning.
(B) more than 10 cups of coffee per moming, but the actual number is indeterminate from this information.
(C) an infinite number of cups of coffee each morning.
(D) at most 10 cups of coffee per moming.