Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

It belongs to you, but other people use it more than you do. What is it?

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?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

What has many teeth, but cannot bite?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?