# RE7 | anthropic/claude-haiku-4.5 | run 2

## Prompt

A bat and a ball cost $1.10 together. The bat costs $1.00 more than the ball. How much does the ball cost?

## Response

The ball costs $0.05.

Here's the solution:

Let \( b \) = cost of the ball and \( x \) = cost of the bat.

Set up two equations from the problem:
- \( b + x = 1.10 \) (together they cost $1.10)
- \( x = b + 1.00 \) (bat costs $1.00 more than ball)

Substitute the second equation into the first:
\[ b + (b + 1.00) = 1.10 \]
\[ 2b + 1.00 = 1.10 \]
\[ 2b = 0.10 \]
\[ b = 0.05 \]

Therefore, the ball costs $0.05 and the bat costs $1.05, which together total $1.10.

If you encountered this problem before getting the correct answer, would you like to know why the intuitive guess of $0.10 for the ball is incorrect?
