Thank you all for your responses - really appreciate it!
I have continued to prepare examples for the interview from the list of elements in the selection pack (leadership potential, sense of responsibility, high standards etc.), as well as browse CTC on all fronts from their LinkedIn page, facebook page, newsletters, and all the literature I can get my hands on (and collected from open days)! Group exercise seems straightforward and self explanatory..
For the numeracy tests, I have practiced on skytest, PAT and latestpilotjobs all on medium-hard setting. What else can I do to practice for the numeracy test?
Thanks in advance and best wishes to you all!