Prisoner to be freed

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 1 and 2, each of which can be in either up or the down 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 flip one switch when he visits the switch room, and may only flip one of the switches. Then he'll be led back to his cell.

"No one else will be allowed to alter the switches until I lead the next prisoner into the switch room. 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. I will not touch the switches, if I wanted you dead you would already be dead.

"Given enough time, everyone will eventually visit the switch room the same number of times as everyone else. At any time, anyone may declare to me, 'We have all visited the switch room.'

"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 all die horribly. You will be carefully monitored, and any attempt to break any of these rules will result in instant death to all of you"

What is the strategy they come up with so that they can be free?




Similar Riddles

In a holy town, three temples sit in a row identical in almost every manner including a holy well in front of them. A pilgrim comes to visit the temples with some flowers in his basket.

At the first temple, he takes some water from the holy well and sprinkles it on the flowers to wash them. To his astonishment, the number of flowers in his basket doubles up. He offers a few of them at the temple and turns back to visit the second temple.

At the second temple, he again takes some water from the holy well and sprinkles it on the flowers to wash them. Again the number of flowers double up in number. He offers some of them at the temple and turns back to visit the third temple.

At the third temple, he repeats the process and the number of flowers doubles up yet again. He offers all the flowers in the third temple.

Now, the pilgrim offered the same number of flowers in all the temples. Can you find out the minimum number of flowers he must have had initially? How many flowers did he offer to god in each of the three temples?

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Henry is a bit incredulous that his ex-wife would carry out the punishment, and a bit sad that she was always such a rule follower. He steels himself as Gretchen loads the chambers, spins the revolver, and pulls the trigger. Whew! It was blank. Then Gretchen asks, 'Do you want me to pull the trigger again, or should I spin the chamber a second time before pulling the trigger?'

What should Henry choose?

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How do you divide the marbles up so that you have the greatest probability of choosing a WHITE marble?

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Can you think of two more such country's unions that could produce similar names like Japanama by overlapping their three letters?

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