Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

Queen Elizabeth organised a royal party.

To Avoid uninvited guest royal family set a password.
Jack (an uninvited person) plan to enter the party. He stand nearby the door.

First guest comes, the security person said 'twelve' and guest replied with six.
Second guest comes , the security person said 'six' and guest replied with 'three'.

Jack thought is enough and he walked to the entry point. The security person said 'eight' , Jack replied smilingly 'four'.
He was immediately thrown out of the party. why ?

What does this rebus puzzle means ?

How can a man go eight days without sleep?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Can you decipher the below rebus?

PBLUESAISNUERSES

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

What makes this number unique: 8,549,176,320?

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?

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?