Question

Any number that is divisible by 4 is also divisible by 8. Find a counterexample to show that the conjecture is false

Answer 1

if anythings that is divisible by 4 and by 8 then 12 would be a example to prove it false

Answer 2

' 4 ' itself is a fine counterexample.
4 is divisible by 4 but not by 8 .

Any odd-multiple of 4 is another counterexample.
In other words, only even-multiples of 4 are divisible by 8 .