Which is the rope you never skip with?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

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 ?

How many sides does a circle have?

When is the top of a mountain similar to a savings account?

A sundial has the fewest moving parts of any timepiece. Which has the most?

What's a single-digit number with no value?

What is next number in the pattern below:

131 517 192 123 ?

What is the next number in this matchsticks series riddle?

Move three sticks of the spiral below to form a square.