A few riddles...

Heres a few of the riddles I've got. I'm a newb to this forum so you've probably seen them before...but here goes.


1) Who makes it, has no need of it. Who buys it, has no use for it. Who uses it can neither see nor feel it. What is it?

2) Five hundred begins it, five hundred ends it,
Five in the middle is seen;
First of all figures, the first of all letters,
Take up their stations between.
Join all together, and then you will bring
Before you the name of an eminent king.

3) A man wanted to enter an exclusive club but did not know the password that was required. He waited by the door and listened. A club member knocked on the door and the doorman said, "twelve." The member replied, "six " and was let in. A second member came to the door and the doorman said, "six." The member replied, "three" and was let in. The man thought he had heard enough and walked up to the door. The doorman said ,"ten" and the man replied, "five." But he was not let in.

What should he have said?

4) A sheik announced that a race would decide which of his two sons would inherit all his wealth. The sons were to ride their camels to a certain distant city. The son whose camel reached the city last would be given all the sheik's wealth.

The two sons set out on the journey. After severals days of aimless wandering, they met and agreed to seek the advice of a wiseman. After listening to the wiseman's advice, the two sons rode the camels as quickly as possible to the designated city.

What was it that the wiseman told the two sons? They did not agree to split the wealth, and their father's decree would be followed.