What's the only room from which no one can enter or leave

I can be cracked, made, told, and played. What am I?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

There are three boxes on a table. One of the box contains Gold and the other two are empty. A printed message contains in each box. One of the message is true and the other two are lies.

The first box says "The Gold is not here".

The Second box says "The Gold is not here".

The Third box says "The Gold is in the Second box".

Which box has the Gold?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

Christina is older than Kareena and Karishma. Katrina is older than Karishma and younger than Kareena. If Kareena has a brother named John, who is older than Christina, who's the youngest?

Count the squares in the matchstick puzzle below?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Why is the Hole below a Lock?