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?

Which word does the below Plexor means ?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

I’m tall when I’m young, and I’m short when I’m old. What am I?

Buy me, smell me or deliver me, I do not change.

Who am I?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

Can you find a five letter word that is left with only two letters if one is removed?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain