If the questions are duplicates, then the newer questions should be closed as duplicates.
If the questions are not duplicates, but related in some way, then you can answer them, but I would rather adapt the answer to the question, which means:
- If the question involves code, show the code that should be written using the solution you propose
- If there are other solutions, and you know them, give a hint about them
If the questions are not duplicates, there is something that makes each of them unique in someway, and I would use that element to give a different answer for each question.
IMO, copying-and-pasting an answer is not answering a question, and from the point of view of who ask the question getting an answer that is a carbon copy of another someway-related question could be a bad experience. I imagine it would be a bad experience if I ask a question to a person, and I get the same answer given to the person before me, and the same answer given to the next person. At least, it would tell me I was not listened carefully.
As side note, duplicate answers given from the same user to different questions are automatically flagged, and the flag is visible to 10K users, not just moderators.