There was a strange boy who was born before his father. How can this be possible?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

I cannot talk, but I always reply when spoken to. What am I?

0 0 0 = 6
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

You can use any mathematical symbols in the space provided to make all above algebraic expressions true.

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?

How can one talk without saying a single word?