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

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Asked by Neha on 14 Sep 2025


What does below Rebus say?

XLR8

Asked by Neha on 10 May 2021

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Asked by Neha on 27 Aug 2021


Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

Asked by Neha on 14 May 2021

How many times can you subtract the number two from the number fifty?

Asked by Neha on 12 Mar 2022

After a heavy Thanksgiving meal, the night watchman went to work. In the morning, he told his boss he had dreamed that a saboteur planted a bomb in the factory and that he felt it was a warning. The boss promptly fired him. Worker confused, Why boss fire him?

Asked by Neha on 28 Dec 2025


The chance of Mr John winning the lottery is 10%. All participants lined up and Mr John is 4th in the row. The first three participants lose the lottery.

What is the chance of Mr John now?

Asked by Neha on 09 Aug 2023

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Asked by Neha on 02 Jun 2024

The dirtier I get, the whiter I look. Who am I?

Asked by Neha on 12 Jan 2026


A dead body is found outside a multi-story multinational company. The case is reported and a homicide detective is called on the crime scene.

He looks at the body and then towards the building. From the position of the body, it is evident that the victim committed suicide. He goes to the first floor of the building and then walks in the direction of the dead body, opens the window and toss a coin in the air.

He goes to second floor and again repeats the process. He keeps doing this till he is done on all the floors. Then he returns back to the floor and tells his team that it is a murder.

How in heaven did he deduce that?

Asked by Neha on 10 Sep 2021

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.