Let's Have a Little Fun

I think it's time for some fun. Some riddle perhaps. And just for even more fun -  a prize for whoever answers them all correctly first. Your choice of scrabble tile pendants (with a silver ball chain).
Leave your answers in the comment section and whoever answers all 5 riddles correctly first wins!
(If I recall the last time I did this we had winner within like an hour or two so this time they'll be harder! )

Here we go....

1. Two spies want to get in an enemy's military base. In order to get in they have to give the correct countersign to the guard at the gate after he gives them the sign. So they wait hidden nearby the gate so that they will overhear the countersign from another soldier.

One soldier comes and the guard gives the sign: "6".The soldier answers "3".The guard lets him pass. Another soldier comes.The guard says "12" and the soldier gives the answer "6".The guard lets him pass. So, the first spy goes at the gate and the guard asks says "10".The spy, sure that he knew the answer as he was, says "5". Immediately, the guard shoots him dead.

Then the other spy, who saw that the other spy was killed when he gave the countersign, had now understood what the right answer would be, whatever the guard's sign was.So, he walks to the gate and the guard says "8".The spy gives the correct answer and the guard lets him in. What was the answer that the spy gave?

2.  You have been imprisoned in a castle and your prison guards decide to tempt you with freedom, but at a big risk. They show you 2 doors, each with a guard standing in front, one door leads to the hanging gallows and the other leads directly out the castle and into freedom.
You are told that one guard is a liar, and will always lie and the other guard will speak only the truth.
You have no idea which guard is which, or what door is what. Your prison guards laugh and inform you that you may only ask one question.
What question do you ask?

3.  What number is missing from the sequence below?
     8 5 4 9 1 _ 6 10 3 2 0

4. A man was found murdered on Sunday morning. His wife immediately called the police. The police questioned the wife and staff and got these alibis:

The Wife said she was sleeping.
The Cook was cooking breakfast.
The Gardener was picking vegetables.
The Maid was getting the mail.
The Butler was cleaning the closet.

The police instantly arrested the murdered. Who did it and how did they know?

5. 2 fathers and 2 sons go fishing. Each of them catches one fish. So why do they bring home only 3 fish?
Have fun and good luck!!