We are having a lot of questions on combinatorics which can be considered as a case of arranging balls in boxes. That would make a total of $6$ different cases and I would like to make an article to discuss these so that I can reference to in future. Is it acceptable to ask a question and then answer my own question?
It is expressly permitted to answer your own question. That's why the asking-a-question form has a box for simultaneously posting an answer to the question.
If you do this you should link your question and answer from the list of generalizations of common questions mentioned above.