Kids Riddles

Question: Enter one hole and leave three,
once you succeed I'm on thee?

What am I?

Question: What goes up and never comes down?

Question: You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you.

What is the sum of the first page in each book?

Question: A town only has one barber (he is male). The barber only shaves all of the people who do not shave themselves.

So who shaves the barber?

Question: You can rest on my pad without touching the keys.
I will sing all month long as long as you pay your fees.

What am I?