What does it mean?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

Decode this picture on T-Shirt and tell what it says ?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

What is the centre of gravity?

Our product and our sum always give the same answer. Who are we?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

You visit a home for specially-abled children on the occasion of Christmas where you meet with 50 children. You have a box of chocolates containing 50 chocolates exactly.

What if you were asked to one chocolate to each child in a manner that one chocolate still remains in the box? Is it possible?