This is a classic brain teaser! Here's the solution:

The ball costs **5 cents** ($0.05).

Here's why:

*   **Ball:** $0.05
*   **Bat:** $1.05 (which is $1.00 more than the ball)
*   **Total:** $0.05 + $1.05 = $1.10

The common (but incorrect) answer is 10 cents. But if the ball were 10 cents, the bat would have to be $1.10, making the difference only 90 cents, not the required $1.00.
