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

You can see it everyday, But cannot touch it at will. What is it?

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

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

What goes through cities and fields, but never moves?

Find the missing number in the sequence below:

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?