anyone good at math's

[losixxx]

APART FROM CHAZZ

hi
anyone a wizz at math's, got to sit some test's for an interview

http://www.psychometric-success.com/...20Test%201.pdf

most of the stuff is fine but its been a good few years since ive used this sort of stuff and my head's about to explode with questions 17-21 just can't get my head round the pie chart percentage's

so if anyone has an easy way of doing this with basic calculator..mine doesn't do % or fractions or is it worth my spending out on a posh one?

tks