Activities are (for on board only) maths and English, then a group discussion and if you have not been sent home, a final interview.
for station staff you don't do the math and English. You do a listening exercise.
The group discussion will vary on difficulty for everyone. For me it was very easy (as it was for everyone in the room yesterday, we all got on very well and enjoyed it) My only advice here would be, have your say, don't talk over anyone else, if someone is interrupting a lot, let them carry on, they are failing, and try to bring the quiet one into the conversation if you have the opportunity. There are no right or wrong answers, its all about working together as a team.
Best of luck all.