Answer:
Counterexample: 21 which is divisible by 3 but not by 6.
Step-by-step explanation:
Use for example the number 21 which is divisible by 3 rendering 7, but not divisible by 6.
You can find any number with at least a factor of "3", but no factor "2" in it, so any odd number divisible by 3 would work as counterexample.
