Answer
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.
Work Step by Step
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.