If eleven plus two equals one, what does nine plus five equal?

Out of three Friends John, Jacob and Jonny one of them is a king, one is a bureaucrat, and one is a Spy.

The king always tells the truth, the bureaucrat always lies, and the Spy can either lie or tell the truth.

John says: Jonny is a bureaucrat
Jacob says: John is a king
Jonny says: I am a Spy

Tell me, Who is the king, who is the bureaucrat, and who is the Spy?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

How many times can you subtract the number two from the number fifty?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.