I recently created a nice olympiad problem on the invariance principle, and I thought about posting it on Math Stack Exchange. However, I was unsure about it as the community guidelines have not mentioned anything about questions that we have already solved.
This has happened in many other cases, too. Whenever I've solved a really beautiful problem, I have wanted to post the problem and its solution on Math Stack Exchange for other users who might like the problem, and who may post their own solutions to it. However, since this wouldn't exactly be a question, are we allowed to post such questions?
Thanks in advance :)