It's not hard maths but it's the simple maths that if you've left school a while you probably don't remember. It's the normal times, division and all that but then mainly focuses on decimals and moving them, converting percentages, fractions and ratios, and a lot of converting mg to g and ml to l etc. On most uni websites, especially Coventry they have sample tests so have a look what they're like:-)
Yes all of those normal questions as well as a lot of scenarios, no the group interview is a scenario and you just have to discuss it whilst people make notes. Make sure you make your voice hear but don't overpower or interrupt. Make relevant points and try to include legislations and things to sound smart.
The q&a is with other students but remember that you are always being assessed even when you're just sitting down so be chatty to everyone.
Don't worry I was the same when I had my interviews, just be yourself an good luck!