What does this rebus means ?

PROG WORKRESS

John was piloting a plane behind a car but was never able to overtake it. Why?

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

I look at you, you look at me, I raise my right, you raise your left. What am I?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Can you count the number of triangles in the picture below?

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 ?