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

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

On a magical land of Mexico , all the animal in the land are rational.

There are 10 tigers and one goat.
Tiger can eat goat but since it's a magical land , the tiger who eats the goat , turns into goat and then can be eaten by the remaining tiger(s).

If we leave them for some time then how many goat and tiger will be there , when we come back ?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

My location can be determined by the below rebus.
So where am i ?

Which is heavier: a ton of bricks or a ton of feathers?

Can you place six X (crosses) in below board without making three in a row in any way ?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

A person is found murdered in his Chamber. When the crime scene is investigated, the Investigator find out that there is a calendar on which the victim has written a few numbers with his blood. The numbers are 4, 11, 11 and 4.

There are four suspects in the murder, John, Jacob, Anna and Lee. Can you find out who is the murderer?