[Gareth]

I'm having a bad day, and an evil friend sent me this.... took me ages to get the right answer.

I'll put the answer below, so don't cheat but post whether you got it correct or not. Check the first Spoiler after making your first guess

if a bat and ball cost £1.10 and the bat is £1 more expensive than the ball then how much is the ball?????

First Spoiler

Spoiler: 

If you said 10p then you're wrong... try again before checking below

Answer

Spoiler: 

The ball costs 5p and the bat costs £1 more than the ball, ie £1.05, so the bat and the ball costs £1.10