Oh I love this question.
It's 100% a great practice to state a question.
The reason is not for the interviewer, it's actually for you. It's so you know what are the level 2 and level 3 areas you want to include to answer the question.
For example, if you say, “I want to look at the market” or “I want to look at the customers." Well, there are a million things you could look at, a million ways to segment, etc. What you might really mean, is “I want to see if our customers overlap with those of the potential acquisition” and therefore you'll much more easily identify the next levels.
Furthermore, it's much more hypothesis driven and much more interesting for the interviewer (or the client) to be told what the questions are we want to answer than what are the subjects we should discuss.
Happy to explain more. In the meantime, hope this helps!