Puzzle 3: The Switches

The warden meets with 23 new prisoners when they arrive. He tells them, "You may meet today and plan a strategy. But after today, you will be in isolated cells and will have no communication with one another.
"In the prison is a switch room, which contains two light switches labeled A and B, each of which can be in either the 'on' or the 'off' position. I am not telling you their present positions. The switches are not connected to anything.
"After today, from time to time whenever I feel so inclined, I will select one prisoner at random and escort him to the switch room. This prisoner will select one of the two switches and reverse its position. He must move one, but only one of the switches. He can't move both but he can't move none either. Then he'll be led back to his cell.
"No one else will enter the switch room until I lead the next prisoner there, and he'll be instructed to do the same thing. I'm going to choose prisoners at random. I may choose the same guy three times in a row, or I may jump around and come back.
"But, given enough time, everyone will eventually visit the switch room as many times as everyone else. At any time anyone of you may declare to me, 'We have all visited the switch room.' and be 100% sure.
"If it is true, then you will all be set free. If it is false, and somebody has not yet visited the switch room, you will be fed to the alligators."
What is the strategy they come up with so that they can be free?

Puzzle 2: Bad King

A bad king has a cellar of 1000 bottles of delightful and very expensive wine. A neighbouring queen plots to kill the bad king and sends a servant to poison the wine. (Un)fortunately the bad king's guards catch the servant after he has only poisoned one bottle. Alas, the guards don't know which bottle but know that the poison is so strong that even if diluted 1,000,000 times it would still kill the king. Furthermore, it takes one month to have an effect. the bad king decides he will get some of the prisoners in his vast dungeons to drink the wine. Being a clever bad king he knows he needs to murder no more than 10 prisoners - believing he can fob off such a low death rate - and will still be able to drink the rest of the wine at his anniversary party in 5 weeks time.

Explain how....

Puzzle 1: The $21 question

Mike and Todd have $21 between them. Mike has $20 more than Todd. How much does each have (you can't use fractions in the answer)?

3 Logical Puzzles

In the next few posts, I will upload three different logic puzzles which I thought were interesting. I won't put up the answer and people can reply in the comment sections. If you have already seen these puzzles, don't give the answers. I don't know the solutions to two of them yet myself!! :-)
Are you ready... get set?
GOOOOOO!!

Math Game

1. pick a number between 0 and 9.
2. multiply that number by nine.
3. if it is two digits, add the two digits together. eg; 14, 1+4 = 5
4. now subtract 5 from the now one digit number
5. match up their number with one in the alphabet. 1=a, 2=b,...
6. think of a country that starts with that letter
7. think of an animal that starts with the last letter of the country name
8. then think of a color that starts with the last letter of the animal...

look at the comments for something interesting....