Hi Squeeky... good luck for your interview! I had mine a couple of weeks ago and found out last week that I got it!
The interview was fine... a group session in the morning which is quite relaxed... they'll ask you really simple qs about yourself... find out what you do at the moment etc. During a group activity, they'll take individuals to one side to ask you why you want to be cabin crew and why you want to work for Virgin. The group stage takes a couple of hours. After that, you take a break and then the interviewers split the group.. a group to have interviews in the afternoon, and a group to go home.
I didn't have to do a maths test, the test involved reading a page giving a scenario and then answering qs on it... so a memory test more than anything, and nothing tooooo difficult!
Anyway, keep us posted on how you get on!! Good luck!!!!
xx