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 the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

Make Two Square

Asked by Neha on 14 May 2021


There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

Asked by Neha on 28 Sep 2021

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Asked by Neha on 16 May 2022


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

What Is It?

Asked by Neha on 27 Jun 2023

Find the smallest sentence with all the English alphabet.

Asked by Neha on 21 Sep 2025

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

Asked by Neha on 11 Jul 2023


I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Asked by Neha on 28 Mar 2023

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

Asked by Neha on 21 Aug 2024

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

Asked by Neha on 14 Feb 2022


My sock drawer has 26 blue socks, 13 pink socks, 33 green socks, and 12 red socks, how many socks would I have to pull out in the dark to be sure I had a matching pair?

Asked by Neha on 13 May 2026

Hot Articles

Amazing Facts

Gamers

In 2011, people playing Foldit, an online puzzle game about protein folding, resolved the structure of an enzyme that causes an Aids-like disease in monkeys. Researchers had been working on the problem for 13 years. The gamers solved it in three weeks.