After 1hr thinking in a problem, I gave up, and then I asked a question on math SE. Then, 1 minute after posting it, I realized the answer. Did that already happen to you? What should one do in this situation? Should one delete the question? Or let it for others?
In particular, since this question of mine is of the type "please spot my mistake" I don't think it is useful for other people, and I guess I should have deleted it. I would like to know what to do in such cases.
With that in mind, extending from the boundaries of my question, and going to to all possible questions, I ask: When exactly one should delete a question immediately after its posted because one found the answer? Always? Never? Depends on the question? Which types of questions should be deleted?