The marginal utility for newspaper is zero on the other hand the marginal utility for soda and candy are positive
Step-by-step explanation:
The newspapers that are sold in vending machines have zero marginal utility because all the news which are given in the newspaper are identical and they are same they do not have multi purpose uses and hence they allow the consumers to take more than what they pay
The soda vending and the candy vending machines have positive marginal utility they have different brands of sodas and candies and hence they allow the consumers to take only one at a time