The warden meets with 23 new prisoners when they arrive. He tells them, "You may meet today and plan a strategy. But after today, you will be in isolated cells and will have no communication with one another.
"In the prison is a switch room, which contains two light switches labeled 1 and 2, each of which can be in either up or the down position. I am not telling you their present positions. The switches are not connected to anything.
"After today, from time to time whenever I feel so inclined, I will select one prisoner at random and escort him to the switch room. This prisoner will select one of the two switches and reverse its position. He must flip one switch when he visits the switch room, and may only flip one of the switches. Then he'll be led back to his cell.
"No one else will be allowed to alter the switches until I lead the next prisoner into the switch room. I'm going to choose prisoners at random. I may choose the same guy three times in a row, or I may jump around and come back. I will not touch the switches, if I wanted you dead you would already be dead.
"Given enough time, everyone will eventually visit the switch room the same number of times as everyone else. At any time, anyone may declare to me, 'We have all visited the switch room.'
"If it is true, then you will all be set free. If it is false, and somebody has not yet visited the switch room, you will all die horribly. You will be carefully monitored, and any attempt to break any of these rules will result in instant death to all of you"
What is the strategy they come up with so that they can be free?
Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.
How come ?
Find the hidden tiger in the given optical illusion ?
Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?
I have no doors but I have keys, I have no rooms but I have space, you can enter but you canâ€™t leave! What am I?
Which is heavier: a ton of bricks or a ton of feathers?
If,
A = 1
B = 2
C = 3
...
...
Z = 26.
Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.
A man dies of old age on his 25 birthday. How is this possible?
When my father was 31 I was 8. Now he is twice as old as me. How old am I?
You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?
(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)
Jigsaw puzzles soared in popularity during the great depression, as they provided a cheap, long-lasting, recyclable form of entertainment.