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

One evening there was a murder in the home of a married couple, their son and daughter. One of these four people murdered one of the others. One of the members of the family witnessed the crime.

The other one helped the murderer.

These are the things we know for sure:

1. The witness and the one who helped the murderer were not of the same sex.

2. The oldest person and the witness were not of the same sex.

3. The youngest person and the victim were not of the same sex.

4. The one who helped the murderer was older than the victim.

5. The father was the oldest member of the family.

6. The murderer was not the youngest member of the family.

Who was the murderer?

Asked by Neha on 20 Sep 2025


They are three errirs in this question. Can you find them?

Asked by Neha on 13 May 2025

When we see 2 but call 10?

Asked by Neha on 14 Oct 2023


The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?

Replace the (?)

Asked by Neha on 30 Jun 2023

Can you count the number of matches in the picture below ?


Count the Matches

Asked by Neha on 14 May 2021

James bond was pushed out of an aeroplane without any parachute.
He survived, How come?

Asked by Neha on 28 Sep 2024


Solve this riddle by finding the odd one out from the rest.

Odd One Out in the Shapes Riddle

Asked by Neha on 18 Apr 2021

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

Asked by Neha on 19 Feb 2025

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Asked by Neha on 23 Oct 2021


In the Thar desert, 3 men found a big 24L Jar is full of water. Since there is a shortage of water so they decided to distribute the water among themselves such that they all have equal amounts of it. But they only have a 13L, a 5L and an 11-litre Jar.

How do they do it?

Asked by Neha on 11 Jun 2024

Hot Articles

Amazing Facts

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.