Written exercise is very time pressing. You need to be able to read fast and write fast with a good report structure.
Only other thing to worry about is the group exercise. I had two people in my group, and they agreed to one thing, while I had a dissenting view. I tried to convince them that I was right by explaining my logic and presenting the evidence, but they wouldn’t listen. I didnt want to look like a jackass, so I said that I understood what they were trying to get at, but we lacked some information. If we could made two assumptions about the data provided, then their argument was valid.
The important thing to remember for the group exercise is that you need to be assertive without dominating the discussion.