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

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Asked by Neha on 16 May 2022


Complete the given grid with valid words. You can only use the letters AAEEIIMMPPTT.

Hint: The grid reads the same across as down.

English Winglish

Asked by Neha on 18 Jun 2024

A man and his wife were doing missionary work near the city of Nairobi in the country of Kenya in eastern Africa. Their housing had not yet been completed, so the man, the woman, and their six year old daughter were spending a few nights in the jungle in three small pup tents. During their third night there, the woman was awakened by the call of a hyena passing by, so she got out of her tent to see if her young daughter had been frightened by the noise. As she peered into her daughter's tent she was surprised to see the dark figures of lion, a panther, and a cheetah which were curled up next to her daughter. Seeing her daughter was asleep and unharmed, the woman slowly and quietly withdrew from the tent, and simply returned to her own tent and went back to bed. How could this child's mother leave her daughter in such a dangerous situation, and simply ignore what she had just witnessed without intervening in some way? How can such emotional coldness ever be explained; or is there something here we are missing?

Asked by Neha on 04 Apr 2022


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

Distances from you to certain cities are written below.

BERLIN 200 miles

PARIS 300 miles

ROME 400 milesAMSTERDAM 300 miles

CARDIFF ??? miles

How far should it be to Cardiff ?

Asked by Neha on 25 Feb 2021

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

Asked by Neha on 25 May 2024


Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

Asked by Neha on 11 Oct 2024

A little girl goes to the store and buys one dozen eggs. As she is going home, all but three break. How many eggs are left unbroken?

Asked by Neha on 02 Mar 2022

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

Asked by Neha on 30 Sep 2025


There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Rearrange Paper

Asked by Neha on 18 Aug 2023

Hot Articles

Amazing Facts

Jigsaw puzzles

Jigsaw puzzles soared in popularity during the great depression, as they provided a cheap, long-lasting, recyclable form of entertainment.