Type a counter-example that would have to exist in order for the conclusion to be false.

5> 0, 6> 0, 12> 0, 16> 0, 20> 0, 100> 0.

conclusion: all numbers are greater than 0.

counterexample:

From the statement above, below is the sequence of expressions.
5> 0, 6> 0, 12> 0, 16> 0, 20> 0, 100> 0.

And it gave a conclusion that:
Conclusion: All numbers are greater than 0.

The glitch here is very obvious. It directly says All numbers are greater than 0. This means all numbers.

A number could be -12, 0, -25
-12 > 0 is FALSE
0 > 0 is FALSE
-25 > 0 is FALSE

That would be enough to prove the conclusion, wrong.