The maths questions in the computer test (the ones at the same time as the colliding thing) are basic arithmetic like adding and subtracting. Could be anything like 9+2 or 5499-3924, etc. There are multi-choice answers for these, 4 or 5 to choose from I think. They are literally only up for 2 seconds or so, so you have to be fairly quick.
The stage 2 interview should be about 20 mins, not an hour. The questions are set, and the interviewer doesn't really talk back except asking the next question. I think they have a list of key words or something that they listen out for you to say (no idea what they are, but pretty common sense....like obviously don't say I have no confidence, I'm pessimistic, etc....).
And that is that.