A user asked a question with multiple unrelated parts (three problems and their answers from a book, which the OP wanted help in understanding). Someone advised that the different problems in this "question" really should be posted as three separate questions on the site, so the OP dutifully started to post the questions individually.
The OP also expressed willingness to delete the original question. But in the meantime, someone had posted an answer to the original (multi-part) question, addressing the first problem in the list. The OP accepted this answer.
It's unclear to me what advice to give to the OP on how to clean up this situation (if indeed it needs "cleaning up"). I suppose that deleting the question at this point would (at least in effect) delete an answer that evidently had some value and had earned the answerer some reputation.
Provided that the reposting of the first part of the question doesn't itself get any upvoted answers, I suppose that in this case the original (multi-part) question could be edited by removing the second and third parts (which weren't yet answered). This isn't a general approach to all such situations, however. (For example, answers to two different parts might have been posted.)
Or is this just the sort of thing to bring to a moderator's attention?