What is a counterexample for the conjecture?
Conjecture: Any number that is divisible by 2 is also divisible by 4.
A counterexample for this conjecture is the number 6.
6 is divisible by 2 since 6 divided by 2 equals 3.
However, 6 is not divisible by 4 since dividing 6 by 4 results in a remainder of 2.