What is the Math.SE take on questions like Perfect set without rationals, whose answer, judging from the comment, is known to the OP?
I think maybe this question is a "seed" question. See OP's profile:
I am a Mathoverflow user who wants to enable this site to have high quality, as opposed to being too sloppy a site. So I am seeding the site with good quality questions that are suitable for all college students; but won't be accepted in MathOverflow. I also want this site to be a home to sensible questions that are brutally closed by the question-closers in MathOverflow.