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?

How to answer

$0.05 (5 cents). Not $0.10! If ball = $0.10, then bat = $1.10, total = $1.20 (too high). Let ball = x. Bat = x + $1.00. Total: x + (x + $1.00) = $1.10. So 2x = $0.10, x = $0.05. Ball = $0.05, Bat = $1.05.