I had to give a presentation as to how I would give a lesson to KS3 pupils to the interviewer, explaining the information to him as if he were the pupil himself.

They basically give you a topic that before hand and you are asked to present on it during the interview. It's not anything hard, just basic math or English depending on the subject you choose. They will ask you some behavioral questions. Why team up, why tutoring just to see if you have the right motivation. And then you are required to do the presentation in 5 minutes. As I said, very simple math question which they will let you prepare for beforehand. Nothing too hard.