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
Different Shapes And Sizes
I'm white but I'm not a sheet of paper
I come in different shapes and sizes but I'm not a snowflake
I can be broken but Im not a window
I can be brittle but Im not peanut butter
I'm sometimes humerus but Im not funny
I am?
I come in different shapes and sizes but I'm not a snowflake
I can be broken but Im not a window
I can be brittle but Im not peanut butter
I'm sometimes humerus but Im not funny
I am?
Hint:
Trapped With The Army
A man got trapped with the army, there were two papers, one said yes the other no. A man in the army said if you get the paper that sees no I will kill you, another man comes in the room sees I put no on both papers. How does he get out of it?
Hint:
He eats one. The man looks at the paper it sees no, so he thought the one the guy ate was yes. Did you answer this riddle correctly?
YES NO
YES NO
It Floats Up To The Top
Blow this thing up nice and big
But do not let it pop
When its filled with helium
It floats up to the top
What is it?
But do not let it pop
When its filled with helium
It floats up to the top
What is it?
Hint:
I Float Higher
Im something that gets inflated
But I am not a tire
And when Im filled with helium
Let go and I float higher
What am I?
But I am not a tire
And when Im filled with helium
Let go and I float higher
What am I?
Hint:
My Life Hangs By A Thread Riddle
I have joy in bringing two together, but darning my existence! My life hangs by a thread, filled with ups, downs and resistance! I am a?
Hint:
You See A Boat Riddle
You see a boat filled with people. It has not sunk, but when you look again, you don't see a single person there. Why?
Hint:
If A Door Number Fitter Riddle
In a new hotel containing 100 rooms, Tom was hired to paint the numbers from 1-100 on the doors. How many times will Tom have to paint the number 8?
Hint:
The answer is 20. Many people have been guessing anywhere from 9 to 19, but the correct answer is 20. Did you answer this riddle correctly?
YES NO
YES NO
A Zombie A Mummy And A Ghost Bought A House Riddle
A zombie, a mummy, and a ghost bought a house. It has all of the usual rooms except for one. What room won't you find?
Hint:
I Have No Doors But I Have Keys Riddle
I have no doors but I have keys, I have no rooms but I do have a space, you can enter but you can never leave, what am i?
Hint:
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