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

What building has the most stories?

Asked by Neha on 21 Feb 2022


There is a jar in which there are two types of candies.
20 blueberries and 16 strawberries. You perform the following steps:
1) You take out two candies.
2) If the two candies are of the same flavour, you add a blueberry one otherwise, you add the strawberry one.

You repeat these two steps till there is just one candy remaining in the jar. Which flavoured candy will be left?

Asked by Neha on 30 Aug 2023

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Asked by Neha on 03 Jun 2023


Can you find out the remainder when 3^300 is divided by 5?

Asked by Neha on 31 Oct 2023

Can you find the hidden animal in the picture below?

Find Animal In Picture Riddle

Asked by Neha on 14 Apr 2021

Which Burger Is Different in below image?

Odd Man out

Asked by Neha on 09 Feb 2023


What does this mean?

CCCCCCC

Asked by Neha on 19 May 2025

What word begins and ends with an E, but has only one letter?

Asked by Neha on 21 Oct 2021

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

Asked by Neha on 23 Apr 2025


I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

Asked by Neha on 19 Mar 2025

Hot Articles

Amazing Facts

Gambling

In Canada, a mathematical puzzle must be solved in order to win the lottery to classify it as a “game of skill” not gambling.