Dave,
I think your chances are 6.22E10. Does that help?
Then again 88.6% of statistics are made up. Apparently.
Maths is an essential requirement. The RAF standard is not much more than PPL (lots of 'mental dead reckoning' and 'rules of thumb' dependant on aircraft type). If you get the required quals and pass the PPL exams, go for it! Good luck.