9514 1404 393
Answer:
All positive integers
Explanation:
The domain of the variable in the cost function is the set of values it might reasonably assume. Since we count movies using integers starting at 1, the reasonable domain is ...
All positive integers
__
Additional comment
We know there is an upper limit. That limit is the number of movies offered such that the summer pass price is valid. We suspect it will be less than two or three hundred. For the purpose here, the reasonable choice is "positive integers."