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?

In which direction should the missing arrow point?

Spot what is wrong here in below Picture?

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

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
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I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

What Adam and Eve do not have but the rest of the people have?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?