Fun Riddles

Question: There are five people at a table and a pie sliced into 5 pieces. Each person has a piece of pie in front of them, yet the pie tin still has a piece of pie in it. How is this possible?

Question: When you do not know what I am, then I am something. But when you know what I am, then I am nothing. What am I?

Question: I have two arms, but fingers I have none. I've got two feet, but I cannot run. I carry well, but I carry best with my feet off the ground. What am I?

Question: Timmy's mother has three children. The first was named April. The next was named May.

What is the final one's name?

Question: What kind of coat can only be put on when wet?