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
Extraterrestrial Flower Riddle
Hint:
I Am Food That Explodes Riddle
Hint:
You Answer Me
Hint:
Alone I Am 24th
Hint: I appear in the alphabet.
The letter 'x'. It is the 24th letter of the alphabet, XX in Roman numerals is 20, and XXX is a label for movies that are very inappropriate (unclean). Did you answer this riddle correctly?
YES NO
YES NO
Without Me You Would Be Lost
I guide you but you can't hear me. Without me you would be lost. I keep going and won't be stopped. What am I?
Hint:
The Old Horror House
There is an old horror house. It has no electricity, plumbing, or power of any sort. You go inside and see three doors. Each door has a number on it. In each door is a way for you to die. In door number one, you die by getting eaten by a lion. In door number two, you die by getting murdered. In door number three, you die by electric chair. You may not turn back so you have to go through a door.
Which door do you go through?
Which door do you go through?
Hint:
Go through number three. You'll survive because it's an electric chair and there is no electricity. Did you answer this riddle correctly?
YES NO
YES NO
Flying House Riddle
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Asking Without Answering Riddle
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Higher Than A House
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The Left Handed Dog
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The Exam Cheater Riddle
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A Green House Riddle
Hint:
A greenhouse (for plants) is made of glass generally so it is clear. Did you answer this riddle correctly?
YES NO
YES NO
Jumping Higher Than A House
Hint:
On Top A Joppa House Riddle
There was a man who went one day
On top a Joppa house to pray,
And while he waited for his meat
He dreamed he saw a great big sheet
Let down from heaven, and inside
Fowls and creeping things did ride,
The one who prayed was told to eat,
For God had cleansed this "common" meat.
Who was he?
On top a Joppa house to pray,
And while he waited for his meat
He dreamed he saw a great big sheet
Let down from heaven, and inside
Fowls and creeping things did ride,
The one who prayed was told to eat,
For God had cleansed this "common" meat.
Who was he?
Hint:
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