Thinking Mathematically (6th Edition)

The difference between two numbers, $4$ and $3$, is $1$, which is an odd number, but 4 is an even number, and not an odd number.
We need to find a counterexample to the statement: If the difference between two numbers is odd, then the two numbers are both odd. One such counterexample would be the numbers $4$ and $3$. $4 - 3 = 1$ $1$ is an odd number $4$ is not an odd number The difference between two numbers, $4$ and $3$, is $1$, which is an odd number, but 4 is an even number, and not an odd number.