Can you think of any three-dimensional shape that comprises of exactly two surfaces?

What has hands, but can’t clap?

How can you tell a raw egg from a hard-boiled egg?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Two old friends, Jack and Jill, meet after a long time, and discussing as:

Jack: Hey, how are you, man?

Bill: Not bad, got married and I have three kids now.

Jack: That's awesome. How old are they?

Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.

Jack: Cool..But I still don't know.

Bill: My eldest kid just started taking piano lessons.

Jack: Oh, now I get it.

How old are Bill's kids?

For this puzzle, you might have to find logic in something illogical. But hey, it's fun and a healthy little break from your strenuous puzzle-solving sessions.

Can you decipher the meaning in the following cluster of letters?

ITIT,NCENTCENT

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

What is black when you buy it, red when you use it, and gray when you throw it away?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?