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

How many times in a given day, minutes and hour clock comes in a straight line ?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Snow and Tyrion are two mad logicians who love betting. They placed 11 Candies at the table and designed a small betting game, in which both of them needed to eat Candies turn by turn with the following rules:

Rule 1: One needs to eat at least one candy.
Rule 2: One cannot eat more than 5 candies.

The one that eats the last candy will lose. Snow won the toss and needs to start. How many candies must Snow earn to make sure that he wins the bet?

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Jigsaw captured 100 people and make them stand in a circle and all these people are labelled as Person1, Person2, Person3... Person100. He made them play a crazy game in which Person 1 shot Person 2 and pass the gun to the next person and so on until one stands alive.

Which person will survive in the end?

Buy me, smell me or deliver me, I do not change.

Who am I?