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

Find out the missing number in the picture attached:

Find the Missing Number

Asked by Neha on 10 Jun 2023


Which word does the below Plexor means ?

Hard Word Plexor

Asked by Neha on 11 May 2021

Why is the Hole below a Lock?

Hole in Lock

Asked by Neha on 23 Jul 2023


It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

Asked by Neha on 17 May 2021

Find the number of squares in the below picture

Count The Squares

Asked by Neha on 13 Apr 2021

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

Asked by Neha on 19 Oct 2024


The king of Octopuses has servants who have six, seven or eight legs. The distinguishing characteristics of the servants is that the one with seven legs always lie but the one with either six or eight legs speak the truth always.

One day, four servants meet and converse:

The black one says, 'We have 28 legs altogether.'

The green one says, 'We have 27 legs altogether.'

The yellow one says, 'We have 26 legs altogether.'

The red one says, 'We have 25 legs altogether.'


Can you identify the colour of the servant who is speaking the truth?

Servants with multiple legs

Asked by Neha on 09 Apr 2021

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

Asked by Neha on 23 May 2025

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Asked by Neha on 09 Jan 2026


Solve the counting riddle by identifying the number of triangles in the given picture.

Count the Triangle Riddle

Asked by Neha on 26 Feb 2026

Hot Articles

Amazing Facts

Rubik’s Cube

The inventor of the Rubik’s Cube didn’t realize he’d built a puzzle until he scrambled it the first time and tried to restore it.