Kids Riddles

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: 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?

Question: I am a cave full of bones,
and the house of a worm.

What am I?

Question: If you have two twins, three triplets and four quadruplets; how many people do you have?

Question: I open to close but I close to open.
I'm surrounded by water but I'm never soaking.

What am I?