I organized a small get together at my home. In the party.............how can i determine which of the guest is right ?

Question

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, its 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 ?

Answer 1

When we tilt the barrel such that the whiskey is touching it's tips, we will be able to see that the liquid level is just above the upper tip of the barrel base only when the whiskey is exactly half filled in the barrel.
This is because at this point the liquid level is the diagonal dividing the volume of the barrel equally.
So after tilting the barrel as described above, If one can see the base of the barrel submerged then it means the barrel is more than half filled or on the other hand if one can see the base of the barrel then it's less than half filed.