Can you make four (4) nines (9) equal 100?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

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

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

An apple seller is hosting a competition. He offers 1000 apples and 10 boxes to the people who pass by. The challenge is to put those 1000 apples in the 10 boxes in such a manner that if he asks for any amount of apples, the person can directly give him the boxes or a combination of boxes. If the person can do it, he promises to give a thousand apples for free.

If you happen to pass by the apple seller, will you be able to win a thousand apples?

Through your logical capabilities, can you make 7 an even?

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

A container contains 100 eggs. They can be either fresh or rotten. What is sure is the fact that there is at least one fresh egg in that container.

If you are asked to pick two eggs randomly from the container, at least one of them will be rotten.

Can you calculate how many eggs in that container are fresh?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

What's the only room from which no one can enter or leave