When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

Can you count the number of matches in the picture below ?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Which tank will fill first?

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 ?