Question

Find a counterexample to show that the conjecture is false. Any number that is divisible by 2 is also divisible by 6.
A.22
B.18
C.36
D.12

Answer 1

18 is divisible by 2 and 6. 18 is not a counter example.
36 is divisible by 2 and 6. 36 is not a counter example.
12 is divisible by 2 and 6. 12 is not a counter example.

Answer 2

The only choice left is 22. 22 is divisible by 2 but not by 6.
So 22 is the counter example.