What is wrong in the below Picture?

What is so fragile that saying its name breaks it?

I organized a small get together at my home.
In the party , i have a barrel with some whiskey in it.

Suddenly Guest 1 say 'I bet this barrel of whiskey is more than half full'.
'No, it's less than half full' Guest 2 replied.

I don't have any measuring instrument and without removing whiskey from it , how can i determine which of the guest is right ?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

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

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

Find out the missing number in the picture attached:

What does this mathematical rebus means ?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?