Prisoners got freed

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?




Similar Riddles

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

Asked by Neha on 03 Sep 2023


John is on an island and there are three crates of fruit that have washed up in front of him. One crate contains only apples. One crate contains only oranges. The other crate contains both apples and oranges.

Each crate is labelled. One reads 'apples', one reads 'oranges', and one reads 'apples and oranges'. He know that NONE of the crates have been labeled correctly - they are all wrong.

If he can only take out and look at just one of the pieces of fruit from just one of the crates, how can he label all of the crates correctly?

Asked by Neha on 07 Jan 2024

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Asked by Neha on 17 Jul 2023


What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

Asked by Neha on 26 Feb 2022

What does this rebus means ?

Rebus For Kids

Asked by Neha on 02 Apr 2025

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

Asked by Neha on 09 Jul 2021


Solve this tricky question. You are trapped in a forest. With you, you have a gun preloaded with two bullets in it. In front of you, there is a tiger, a leopard and a jaguar.

How do you survive?

Asked by Neha on 24 Mar 2024

What word does this rebus represent?

meta meta
meta meta

Asked by Neha on 11 May 2021

I can be cracked, made, told, and played. What am I?

Asked by Neha on 16 Aug 2025


What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

Asked by Neha on 12 May 2023

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Artificial Intelligence

Artificial Intelligence has crushed all human records in the puzzle game “2048,” achieving a high score of 839,732 and beating the game in only 973 moves without using any undo.