## The Answer

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

## Why People Get It Wrong

The intuitive answer is **10 cents**, but that's incorrect. Let's check:

- If the ball = $0.10, the bat would need to cost $1.00 *more*, so $1.10
- $1.10 + $0.10 = **$1.20** ❌ (not $1.10)

## The correct math:

Let the ball = **x**
Then the bat = **x + $1.00**

> x + (x + $1.00) = $1.10
> 2x + $1.00 = $1.10
> 2x = $0.10
> **x = $0.05**

## Checking the answer:
- Ball = $0.05
- Bat = $1.05
- Difference: $1.05 - $0.05 = **$1.00** ✓
- Total: $1.05 + $0.05 = **$1.10** ✓

This is a classic example of a **cognitive bias** where the brain jumps to a quick, intuitive answer rather than working through the logic carefully.
