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?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can you Find and name the hidden bird in the picture below ?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

What is the largest number you can write with just 3 digits?

What occurs twice in a week, once in a year but never in a day?

You can hear me, but you can't touch or see me.

What am I?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?