What does this mathematical rebus means ?

How many letters are in the alphabet?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

What has many keys but can’t open a single lock?

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Can you Find and name the hidden bird in the picture below ?

Can you solve the rebus below?