20/24 (83%), native Briton.
Some of those questions are stupid though, on terms of day to day knowledge on Britain.
If it was actually going to be useful, it would include things about:
- Letting someone go in front of you in the shop queue if they've only got a few things and you've got a basket full.
- Which football teams are "scum" according to supporters of other football teams
- Which one of PJ & Duncan is PJ and which one is Duncan? (Also known as Ant and Dec)
- How to apologise for things, even even they're not your fault
- Why Piers Morgan is a twat
- What things you can have a "cheeky" one of i.e. pints, Greggses, sausage rolls, Nandoses, and girls (if you're MP Lembit Opik).

There's a chance that someone once uploaded a picture of some boobs on it or something, so to "protect the children", our beloved glorious leaders have blocked us from a big chunk of the internet.