Translation:Who are the students and who are the teachers?
That is only if all the teachers were Dr. Who's. :)
Interestingly, this "meg"/"pedig" thing does not work here. Very good thinking, the logic is good, but you cannot do it. Only "és" works here, where we are asking about the subject.
But the answer could do it:
"Mi vagyunk a diákok, ők meg/pedig a tanárok."
It does not matter. The point was, it only works like that, "... Kik meg a tanárok.", if that "Kik" is a name. That is, if "Ki" were a person's name. Or something like that. Then you could say that the Ki's are the teachers.
"Ki" is "Who" in English.
But, in a question form, you cannot use "meg"/"pedig" like that. You connect the two questions with an "és".
Yes; in fact, that's the first interpretation I would understand.
"I see people; please identify for me which of those people are the pupils and which of them are the teachers."
It could also mean "I know that there will be pupils and teachers in my course. Please give me the names of the pupils and the names of the teachers." but the "which of those people" would be more common I think.