That would depend on the size of your classroom. but, typically the answer is no
Your answer, in your set notation, is
{-2, 7}
1. 100000
2. 0.000000000001
3. 400
I'm pretty sure the answer is "A matrix separates rational and irrational numbers." (Note: I'm not that great with memorizing definitions, but I'm pretty sure.) Hope this helps :)