What does below rebus means ?

What has hands, but can’t clap?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

Prove that twice of ten is the same as twice of eleven.

Name a key which is hardest to turn.

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

The peacock is a bird that does not lay eggs. How do they get baby peacocks?

What always comes into a house through the keyhole?

Can you name four days which start with the letter 'T'?