Fun Riddles

Question: You walk into a room with a rabbit holding a carrot, a pig eating slop, and a chimp holding a banana.Which animal in the room is the smartest?

Question: Is an older one-hundred dollar bill worth more than a newer one?

Question: Using 3 periods (.) and 1 question mark (?) make this a logical and grammatically correct sentence:

"That that is is that that is not is not is that it it is"

Question: In Michigan you cannot take a picture of a man in a green hat.

Why?

Question: What grows up and down at the same time?