Especially in the beta, it is natural that people will ask questions they know the answer to. See all of my questions. One of the purposes of the beta is for committed users to seed the site with questions and answers. Knowing the answer to a question you posted does not mean you shouldn't ask the question. Heck, you can even post the answer yourself!
For similar reasons, questions should not be disallowed just because they are 'easy to Google'. First of all, I think that, like StackOverflow, it is part of the goal of this site that when someone has a math question, they should be able to type it into Google and get the related page here, with detailed correct answers, as the top result. Sure, other sites may have the answer, but if we can answer it better, there is still value in reposting the question.
However, that point applies somewhat less to the 32.5=31.5 question. 'Easy to Google' depends on the individual. For this particular question, what would someone stumped by the puzzle for the first time type into Google to find an answer? Or if someone were to ask this question on math.stackexchange, what keywords would they be likely to use, so that the automatic duplicate finder could recognize the question? As far as this goes, the 32.5=31.5 question is a poor one.
Possibly legitimate questions being prohibited because someone might find them fun is just silly to me. There's no way to police that. If it's a real question, and an interesting one, to someone else, it has a place on this site, even if its a joke to you. A more appropriate solution would be to downvote it, or to adjust the tags so that you aren't troubled by such questions.
I think the question is a fair one, but poorly asked. A large part of the justification behind this type of question being asked is to serve as a reference for future users who will want to know the answer. As far as that is concerned, the question is not useful: the majority of the question is in the form of a picture, and there are no unique keywords or tags. If the wording can adjusted to provide a searchable statement of the question, I think it should stay open.