Logic Riddles

Question: What happens when you throw a blue rock into the yellow sea?

Question: No matter how much rain comes down on it it won't get any wetter.

What is it?

Question: No matter how terrible things get for the people of the Arctic, they will not eat a penguin.

Why not?

Question: Mary gets in the shower, but surprisingly her hair is not wet when she gets out. How is this possible?

Question: Two is company and 3 is a crowd. What is 4 and 5?