Logic Riddles

Question: The 22nd and 24th Presidents had the same biological mother and father, but weren't brothers. They were both male, and were never female. Neither were adopted or "switched at birth". How is this possible?

Question: What melts in a freezer?

Question: There is a one story house. The walls are blue, the floor is pink, the stove and cupboards are red. What color are the stairs?

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

Why not?

Question: I am a nice word composed of five letters, but the Romans would call me a numbers.

What am I?