I have teeth but i don't bite. Who Am I ?

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 ?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

You need to arrange three 7 and mathematical symbols to form number 1?

Two in a corner, one in a room, zero in a house, but one in a shelter. What am I?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

If an electric train is travelling south, then which way is the smoke going?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?