A little more context might help here In the situation that there was a list of questions that could have been asked then you would say "which questions were you asked?" in the UK you might often also hear "which questions did you get?", because you "got" some of the questions that were available. In the UK we have a driving test theory exam which has a large set of possible questions, and you get a smaller random selection of these in the actual examination. So sometimes you'll hear someone say "which questions did get on braking distance?" But if there isn't a set list then "what" would be more applicable. Say a friend of yours is a teacher, and they said they tell you that they had received some funny questions from their students. You could respond with an open question: "What questions did they ask you?" or simply "What did they ask?" When there is a very specific answer you are looking for - like if you were interrogating someone, then you find the usage of "what were you asked? / what questions were you asked?". "What were you asked in your interview?" "You spoke to the police? What were you asked and what did you tell them?" Hope that helps

These are all OK. "What" is probably better than "which", unless there was only a limited choice of possible questions. Informally, I might well say: "What did they ask you?" "What questions did they ask?" also works.; or even, "What did they ask you about?" I think "questions" is implied in the "did they ask", and the "you" is probably implied, if you are writing or speaking to a specific individual. But you have a lot of choice here :)