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

Spot the 3 Differences in the given Picture.

I drive at an average speed of 30 miles per hour to the railroad station each morning and catch my train. On a particular morning, there was a lot of traffic and at the halfway point, I had averaged only 15 miles per hour. How fast must I drive for the rest of the way to catch my train?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

People put me on the table and cut me but do not eat me. What am I?