Statistics problem

I have a statistics problem that I just can not figure out the answer to: What is the probability that a namefag is neither a troll nor a moron? I think the answer is 0, but I haven't been able to prove it yet.

>>5
Thats just proves you lack common sense.This isn't /b/.
There people who aren't trolls and morons.(though its doubtful they would stay for long here).