The Secret Santa Exchange
A group of ten friends decide to exchange gifts as secret Santas. Each person writes his or her name on a piece of paper and puts it in a hat. Then each person randomly draws a name from the hat to determine who has him as his or her secret Santa. The secret Santa then makes a gift for the person whose name he drew.
When it's time to exchange presents, each person walks over to the person he made the gift for and holds his or her left hand in his right hand.
What is the probability that the 10 friends holding hands form a single continuous circle?
When it's time to exchange presents, each person walks over to the person he made the gift for and holds his or her left hand in his right hand.
What is the probability that the 10 friends holding hands form a single continuous circle?
Hint: It's not as difficult as it seems.
It's the number of ways the friends can form a circle divided by the number of ways the names can be drawn out of the hat.
1/10
For a group of n friends, there are n! (n factorial) ways to draw the names out of the hat. Since a circle does not have a beginning and end, choose one person as the beginning and end of the circle. There are now (n-1)! ways to distribute the remaining people around the circle. Thus the probability of forming a single circle is
(n-1)! / n!
Since n! = (n-1)! * n (for n > 1), this can be rewritten as
(n-1)! / (n*(n-1)!)
Factoring out the (n-1)! from the numerator and denominator leaves
1/n
as the probability. Did you answer this riddle correctly?
YES NO
For a group of n friends, there are n! (n factorial) ways to draw the names out of the hat. Since a circle does not have a beginning and end, choose one person as the beginning and end of the circle. There are now (n-1)! ways to distribute the remaining people around the circle. Thus the probability of forming a single circle is
(n-1)! / n!
Since n! = (n-1)! * n (for n > 1), this can be rewritten as
(n-1)! / (n*(n-1)!)
Factoring out the (n-1)! from the numerator and denominator leaves
1/n
as the probability. Did you answer this riddle correctly?
YES NO
Exposed To A Disease Riddle
A boy and his father have been exposed to a disease. Sadly, the father rapidly develops a tumor and dies. The boy survives, but desperately needs an operation and is rushed to hospital. A surgeon is called. Upon entering the room and seeing the patient, the surgeon exclaims, Oh no! I cant do the operation. Thats my son!
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I Exist Where There Is Light Riddle
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Archery Experts Riddle
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Karate Expert With A Pig Riddle
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I Am Food That Explodes Riddle
I am a food that explodes. But long before I explode, I am already dead. I can be small, I can be big, and I can be fragrant. My name is literal. What am I?
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Live Between The Extremes
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Explorer Cat Riddle
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Exercising Zombies Riddle
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Murdered On A Sunday Morning
A man is found murdered on a Sunday morning. His wife calls the police, who question the wife and the staff, and are given the following alibis:
the wife says she was sleeping,
the butler was cleaning the closet,
the gardener was picking vegetables,
the maid was getting the mail, and
the cook was preparing breakfast.
Immediately, the police arrest the murderer.
Who did it and how did the police know?
the wife says she was sleeping,
the butler was cleaning the closet,
the gardener was picking vegetables,
the maid was getting the mail, and
the cook was preparing breakfast.
Immediately, the police arrest the murderer.
Who did it and how did the police know?
Hint:
Handcuffed Man Riddle
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A Round House
The police are called to a round house where a man is found dead with a knife wound to the chest. The police investigate and narrow down the suspects to three people: The maid, the wife, and the butcher. When questioned for alibis, the wife said, "I was out buying a dress with my friends, and I found my husband dead upon my return." The butcher said, "I was searching the cupboards for some vegetables to serve for lunch." The maid said, "I was in the other room, dusting the corners." The maid was then arrested. How did the police know it was her?
Hint:
Dead In The Alley Way
The Police find a man dead in the alley way. A bullet hole is in his head. Beside the man is the gun that killed him (with his fingerprints), a handkerchief, and a tape recorder. The Detective pushes play on the tape recorder and hears that it starts from the beginning, and it says: "I'm sorry that I must end my life. I'm in debt and I don't know how to get out of it. I'm sorry..." then a second later he hears the gun go off. Why did the detective file the case as a murder instead of a suicide?
Hint:
The tape started at the beginning and the gun shot was at the end. how could the man rewind the tape if he was already dead? Plus, the murderer could've used the the handkerchief to hold the gun and then puts the man's hand on the gun when he was dead so only his fingerprints were left behind. Did you answer this riddle correctly?
YES NO
YES NO
Pulled Over Blonde
Hint:
Her headlights weren't working, so she was flashing people. Did you answer this riddle correctly?
YES NO
YES NO
You Can Do This To Me
Hint:
A Book: The Police can book you. You book at a restaurant. A book is portable. Did you answer this riddle correctly?
YES NO
YES NO
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