Logic Riddles

Question: This is a bus:

 ____________________
|       |_|    |_|    |_|    |_|       |
|                                        |
|____________________|
     O                         O

Which way is the front of the bus facing (left or right)?

Question: A man built his house above a river between two trees. He attaches his house to the middle of the two tree's trunks. He does this because the river rises by 2 inches each years, but the trees grow 1 inch each year. If his house is 4 inches above the river how long will it take for water to hit his house?

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: 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?