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?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

Why did the Girl throw the butter out of the window?

Why is the Hole below a Lock?

Can you make the below equation true by using any three numbers from "1, 3, 5, 7, 9, 11, 13 and 15"?

( ) + ( ) + ( ) = 30

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

Can you make four (4) nines (9) equal 100?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

Solve below popular number sequence
314 159 265 358 979 323 846 ?

How many letters are in the alphabet?