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 Difficult Riddles

Can it be possible to build a house that has all its four walls facing towards the South?

Asked by Neha on 20 May 2024


There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

Asked by Neha on 10 Apr 2022

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Asked by Neha on 24 Feb 2022


I look at you, you look at me I raise my right, you raise your left. What am I?

Asked by Neha on 24 Apr 2023

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Asked by Neha on 14 Mar 2025

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

Asked by Neha on 22 Nov 2025


I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

Asked by Neha on 21 Mar 2025

What came first, the chicken or the egg?

Asked by Neha on 29 Dec 2025

There is something which you can be arrested for attempting but not for successfully completing.

Asked by Neha on 30 Apr 2024


We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?

Asked by Neha on 15 Feb 2026

Hot Articles

Amazing Facts

Crossword

The day before the 1996 U.S. presidential election, the NYT Crossword contained the clue “Lead story in tomorrow’s newspaper,” the puzzle was built so that both electoral outcomes were correct answers, requiring 7 other clues to have dual responses.