Solve below rebus puzzle?

What work can one never finish?

Which is the correct shadow of the bird?

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 ?

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

Why 1729 is a magic number? Answer Logically.

Why is it very easy to weigh a fish?

What goes through cities and fields, but never moves?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Find the number of squares in the below picture