When my father was 31 I was 8. Now he is twice as old as me. How old am I?

What is wrong in the below Picture?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

Lifeless eyes on my smiling face and watch your child's sleeping place. In their dreams they hold me tight. What am I?

What has no start, end, or centre?

What jumps when it walks and sits when it stands?

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?

How many words can a pen with half refill write?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

You can hear me, but you can't touch or see me.

What am I?