Answer:
3 Movies
Explanation:
The explanation is that when the marginal utility equal the marginal cost you get the maximum of benefit of the transaction as you can see the by every movie that they buy they receive a benefit greater than the price until the benefit and the price is the same $1 it is the point where the students get the most satisfaction of their purchases. In this case with a total number of 3 movies that cost $3 they receive $6 of satisfaction.