I came across Ubuntu screenshot program, which started off as a couple questions mashed together. Although it has since been edited to only ask about screenshot programs, it originally asked for both these and applications for taking notes. As a result, answers have been provided which only answer one of those questions (either the kept one or about the notes) or both. As such, some of the answers' content now appears partially or completely off-topic with regards to the question although they once were not. (This, IMHO, is a great example of why we only allow one question per post.)
How can messy situations like this be best dealt with?