Got it straight away here too.
Easy if you understand that
Ball = cost of ball.
Bat = 100 + Ball
Total = 110
Writing a simple equation gives
Total = Bat + Ball = 1 + Ball +Ball
Thus 2 Balls = 10p which means 1 Ball = nah.....ain't worth a spoiler.
This all happened so fast I doubt if i spent more than 2 seconds thinking about it. Certainly took longer to write this post.