riddle

There's an island of ~300 very intelligent people. They are all (perfect) logicians and they also know that everyone else is a perfect logician. There's no population growth and no one ever dies. Additionally, the inhabitants of the island are either blue-eyed or brown-eyed. As a tradition of...

So I was bored with my friend during Math class and we came up with the following riddle: 0 is not 3 3 is no penis 0 is no penis but 0=3 is a penis?! (with worse handwriting it was way better :P) now a normal riddle: but seriously first 1 was shit. Post your best riddle here :)