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
The 3 Inch Cube Riddle
A 3 inch cube is painted on all sides with RED. The cube is then cut into small cubes of dimension 1 inch. All the so cut cubes are collected and thrown on a flat surface. What is the probability that all the top facing surfaces have RED paint on them?
Hint: Visualize the core of the cube.
ZERO.
The core of the 3 inch cube when cut, has all faces that are not painted. Hence at least one cube with no painted face always occurs. Did you answer this riddle correctly?
YES NO
The core of the 3 inch cube when cut, has all faces that are not painted. Hence at least one cube with no painted face always occurs. Did you answer this riddle correctly?
YES NO
Getting Put Into Shoes
This is a body part
That can be found in twos
It is a type of length
And gets put into shoes
They are?
That can be found in twos
It is a type of length
And gets put into shoes
They are?
Hint:
Laying An Egg Riddle
Hint:
It didn't roll since when did roosters start laying eggs? Did you answer this riddle correctly?
YES NO
YES NO
An Island That Has 3 Gods
There is an Island that has 3 gods. One god always tells a lie, and the other always tells the truth. The third god has a random behavior. To top it off, these three gods, being jerks, answer in their own languages such that you are unable to tell which word, between "ja" or "da", means "no" or "yes". You have 3 questions to work out the True god, the false god, and the Random god.
Hint:
Question 1: (To any of the three gods) If I were to ask you "Is that the random god," would your answer be "ja?" (This questions, no matter the answer, will enable you to tell which god is not random i.e. the god who is either False or True)
Question 2: (To either the True or False god) If I asked you "are you false," would your answer be "ja?"
Question 3: (To the same god you asked the second question) If I asked you "whether the first god I spoke to is random," would your answer be "ja?" Did you answer this riddle correctly?
YES NO
Question 2: (To either the True or False god) If I asked you "are you false," would your answer be "ja?"
Question 3: (To the same god you asked the second question) If I asked you "whether the first god I spoke to is random," would your answer be "ja?" Did you answer this riddle correctly?
YES NO
The Quietest Whimper
I talk, but I do not speak my mind
I hear words, but I do not listen to thoughts
When I wake, all see me
When I sleep, all hear me
Many heads are on my shoulders
Many hands are at my feet
The strongest steel cannot break my visage
But the softest whisper can destroy me
The quietest whimper can be heard.
What am I?
I hear words, but I do not listen to thoughts
When I wake, all see me
When I sleep, all hear me
Many heads are on my shoulders
Many hands are at my feet
The strongest steel cannot break my visage
But the softest whisper can destroy me
The quietest whimper can be heard.
What am I?
Hint:
Making Calls With Skeletons
Hint:
Two Solid Metal Pillars
You are standing on the top one of two solid metal pillars. They are both exactly one kilometer apart from each other and they both stand one kilometer high. There is absolutely nothing around these pillars, but you have one small twig, one small rock and an unlimited supply of rope. Using only the materials named, how can you get from the top of the pillar that you are on to the top of the other pillar?
Hint:
The twig and the rock were simply distractions used to divert you from the real answer. Forget I ever mentioned them. All you need to do is fill the space between you with enough rope that it makes a pile so big that you can walk across it to the other pillar (remember I said you had an unlimited supply of rope). Did you answer this riddle correctly?
YES NO
YES NO
A Country Of Great Animals
What country has great animals
Like a large bird called an emu
A cute and cuddly koala
Or a big hopping kangaroo?
Like a large bird called an emu
A cute and cuddly koala
Or a big hopping kangaroo?
Hint:
A Skirt Around My Bottom
Once I have been chopped
The other end, a star or angel
Is how I get topped
What am I?
Hint:
Alex And The New Neighbor Riddle
So it is the next day. Before they leave, Alex's mother asks them what they are doing, but since Alex despises his mom and doesn't like to talk to her, he just answer with "we are going to the new neighbor, can you leave us alone?" She says "who is the new neighbor." But Alex tells her to shut up and they leave.
They ring the doorbell, the neighbor comes outside, and Alex says hello and then the neighbors name. So what is the neighbors name?
Hint:
The new neighbors name is 'Who.' ...When the mom SUPPOSEDLY asked "Who is the new neighbor?", she wasn't asking; she was making a statement. "Who is [the name of] the new neighbor." Did you answer this riddle correctly?
YES NO
YES NO
I Met A Man On My Way Riddle
Hint:
Only one is going to St. Ives...the narrator! All of the others are coming from St. Ives. The trick is that the listener assumes that all of the others must be totaled up, forgetting that only the narrator is said to be going to St. Ives. If everyone mentioned in the riddle were bound for St. Ives, then the number would be 2,802: the narrator, the man and his seven wives, forty-nine sacks, three hundred forty-three cats, and twenty-four hundred and one kits. Did you answer this riddle correctly?
YES NO
YES NO
When I Am Released To The Wind Riddle
you look away and you pretend,
but away your friends I will send.
What am I?
Hint:
Thanksgiving Pie Riddle
I am a food that's often found,
At Thanksgiving all around.
I'm made with a fruit that's orange and round,
And I'm often topped with a lattice of brown.
What am I?
At Thanksgiving all around.
I'm made with a fruit that's orange and round,
And I'm often topped with a lattice of brown.
What am I?
Hint: This pie is a classic dessert that's often served with a dollop of whipped cream.
Dessert That's Both Hot And Cold
I'm a dessert that's both hot and cold,
And my flavors are a story yet to be told.
I'm made by blending ice cream and milk,
And I'm often topped with whipped cream or a silky silk.
What am I?
And my flavors are a story yet to be told.
I'm made by blending ice cream and milk,
And I'm often topped with whipped cream or a silky silk.
What am I?
Hint: This dessert is a drink that can be enjoyed as a midday pick-me-up or a late-night treat.
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