Fun Riddles

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

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

Why?

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

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