Name a key which is hardest to turn.

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Which point will the car reach to go out?

A generous owner of a company decided to give a bonus of $45 to every man and $60 to every woman on his birthday. But only one-ninth of the men and one-twelfth of the women were present to take the bonus.

Can you calculate the amount of money the owner spent if there were 3552 employees?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

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

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?