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
I'm Not A Dog
I contain water but Im not a bottle
I can be used to make milk but Im not a cow
Im white on the inside but Im not a loaf of bread
I have a husk but Im not a head of corn
I have a hard shell but Im not an egg
Im brown and hairy on the outside but Im not a dog
What am I?
I can be used to make milk but Im not a cow
Im white on the inside but Im not a loaf of bread
I have a husk but Im not a head of corn
I have a hard shell but Im not an egg
Im brown and hairy on the outside but Im not a dog
What am I?
Hint:
Fruit That Contains Water
This is a fruit that contains some water
And can provide milk and oil for cooking
If you ever want to see one growing
On a palm trees where you should be looking
This fruit is a?
And can provide milk and oil for cooking
If you ever want to see one growing
On a palm trees where you should be looking
This fruit is a?
Hint:
A Container Holder Water
Hint:
The Blind Mammals Riddle
The fact this mammal has webbed wings
Makes it a one of a kind
And contrary to the saying
None of these creatures are blind
What are these mammals?
Makes it a one of a kind
And contrary to the saying
None of these creatures are blind
What are these mammals?
Hint:
Most Of The Ozone Layer
Hint:
Hundreds Of These In A Graveyard
There are hundreds of these in a graveyard
But dead bodies it is not
Its what contains all the info as to
Whos in each burial plot
What is it?
But dead bodies it is not
Its what contains all the info as to
Whos in each burial plot
What is it?
Hint:
Found Beneath A Chimney
I can keep you warm but Im not a scarf
Im often made of brick or stone but Im not a wall
I sometimes have a poker but I dont have a deck of cards
I contain logs but Im not a forest
Im found beneath a chimney but Im not Santa
What could I be?
Im often made of brick or stone but Im not a wall
I sometimes have a poker but I dont have a deck of cards
I contain logs but Im not a forest
Im found beneath a chimney but Im not Santa
What could I be?
Hint:
In Your Body Riddle
Im red but Im not a strawberry
I have different types but Im not an apple
I can be pumped but Im not a bicycle tire
I can be donated but Im not money
I contain cells but Im not a jail
Im in your body but Im not your heart
I am?
I have different types but Im not an apple
I can be pumped but Im not a bicycle tire
I can be donated but Im not money
I contain cells but Im not a jail
Im in your body but Im not your heart
I am?
Hint:
I Am Not A Queen
Contrary to my name
I am not a queen
Hold me up to things though
And their length is seen
What could I be?
I am not a queen
Hold me up to things though
And their length is seen
What could I be?
Hint:
100 Offices Riddle
A new medical building containing 100 offices had just been completed. Mark was hired to paint the numbers 1 to 100 on the doors. How many times will Mark have to paint the number nine?
Hint:
Did you say three? The correct answer is twenty (29, 39, and so on). Did you answer this riddle correctly?
YES NO
YES NO
Not An Igloo Riddle
I have shelves but I'm not a bookcase
I have a door but I'm not a cupboard
I have a light but I'm not a lamp
I contain food but I'm not a grocery store
I'm cold inside but I'm not an igloo
What am I?
I have a door but I'm not a cupboard
I have a light but I'm not a lamp
I contain food but I'm not a grocery store
I'm cold inside but I'm not an igloo
What am I?
Hint:
Keeping Your Food Cool
This has something to control its temperature
But it's not an air conditioner unit
It is in your kitchen and it has a door
And it often has meat, cheese and milk in it
But it's not an air conditioner unit
It is in your kitchen and it has a door
And it often has meat, cheese and milk in it
Hint:
Sprouting True Beauty
She's like a model, sprouts true beauty.
Sends sexual shock waves to others and withers away in the end on contests.
Her arms extends freely to reach the crowns, that's shiny and clear and helps her along in life, what is she?
Sends sexual shock waves to others and withers away in the end on contests.
Her arms extends freely to reach the crowns, that's shiny and clear and helps her along in life, what is she?
Hint:
Tub Sink And Towels
Whose name contains three vowels
It often has a tub, sink and some towels
Hint:
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