Riddle: A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
Answer: The ball costs 5c. Not 10c.
One dollar more than 10c is $1.10, $1.10 + 10c is $1.20 One dollar more than 5c is $1.05.
The sum of which is $1.10.