[SilverBirch]

I think you're just reading an ambiguous sentence in a way that obviously wouldn't make sense in context. The question is in a very familiar form: describe a scenario with some assumptions, describe a peturbation, ask what impact the peturbation has. If the context was some annoying internet quiz, the answer might have been a gotcha that the number of people in the queue stay the same.... but this is an econ question it's going to involve how people respond to economic incentives.

[hgsgm]

This is like those LeetCode questions in job interviews, or the interviewer wants a complicated O(n) solution when the problem as stated would be better solved with a simple O(n^2) solution because the maximum problem size is tiny.

It's a mind-reading game of which assumptions the professor/interviewer wants to keep solid which ones are open to change.