Charleygirl, we are scary, aren't we?
Right first things first.
Please read the whole question. Read it again and think about what it actually says. The answer, as previously stated in the OP, is NOT 8.
No-one knows why the student only wears shirts, but take it from me, he doesn't wear T shirts, I have it on good authority. 
There will be no lateral thinking or thinking outside of the box on my watch.
Is that scary enough, Charleygirl ? 
Now for the clever girls' awards.
CraftyGranny, ? May51 ?, Bathsheba? and silverlining (another new pupil, welcome) ?.
Well done!
Oh I'm away for a lie down, being scary is exhausting!