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
Mark And Nancy Riddle
Mark and Nancy have been married for five years. They have a little son named sam.
On a Saturday afternoon, the couple went out to a restaurant to celebrate their fifth anniversary together. Her when they returned in the evening, they found their son dead. There were three other people in the house at the time of the murder. The babysitter said she was ironing sams school uniform for tomorrow. The maid said she was cleaning the corners of the house and the chef said he was chopping vegetables for dinner. Youve been hired to investigate who killed Sam. So who did it?
On a Saturday afternoon, the couple went out to a restaurant to celebrate their fifth anniversary together. Her when they returned in the evening, they found their son dead. There were three other people in the house at the time of the murder. The babysitter said she was ironing sams school uniform for tomorrow. The maid said she was cleaning the corners of the house and the chef said he was chopping vegetables for dinner. Youve been hired to investigate who killed Sam. So who did it?
Hint:
It can be the babysitter or the chef.
Explanation: Both of them are the culprit because if they went for dinner so why the chef is preparing dinner?
And the other is the babysitter because she was ironing the shirt for school tomorrow but it was a Saturday so the next day is Sunday. Did you answer this riddle correctly?
YES NO
Explanation: Both of them are the culprit because if they went for dinner so why the chef is preparing dinner?
And the other is the babysitter because she was ironing the shirt for school tomorrow but it was a Saturday so the next day is Sunday. Did you answer this riddle correctly?
YES NO
10 Fish In A Tank Riddle
Hint: They're inside a tank
What Seven Letter Word
Hint: This word is heavy.
Carefully Counting Kids
Hint:
Who Are These Men?
A man leaves home and turns left three times, only to return home facing two men wearing masks. Who are those two men?
Hint:
An Incorrect Spelling
Hint:
Who Owns The Fish?
There are 5 houses in 5 different colors in a row. In each house lives a person with a different nationality. The 5 owners drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet. No owners have the same pet, smoke the same brand of cigar, or drink the same beverage. Other facts:
1. The Brit lives in the red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The green house is on the immediate left of the white house.
5. The green house's owner drinks coffee.
6. The owner who smokes Pall Mall rears birds.
7. The owner of the yellow house smokes Dunhill.
8. The owner living in the center house drinks milk.
9. The Norwegian lives in the first house.
10. The owner who smokes Blends lives next to the one who keeps cats.
11. The owner who keeps the horse lives next to the one who smokes Dunhill.
12. The owner who smokes Bluemasters drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The owner who smokes Blends lives next to the one who drinks water.
The question is: WHO OWNS THE FISH?
1. The Brit lives in the red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The green house is on the immediate left of the white house.
5. The green house's owner drinks coffee.
6. The owner who smokes Pall Mall rears birds.
7. The owner of the yellow house smokes Dunhill.
8. The owner living in the center house drinks milk.
9. The Norwegian lives in the first house.
10. The owner who smokes Blends lives next to the one who keeps cats.
11. The owner who keeps the horse lives next to the one who smokes Dunhill.
12. The owner who smokes Bluemasters drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The owner who smokes Blends lives next to the one who drinks water.
The question is: WHO OWNS THE FISH?
Hint:
The German sits in his Green House, smoking his Prince cigars, drinking coffee, and watching his FISH.
The rest go like this-
1st House: Yellow, Norwegian, Water, Cats, Dunhill
2nd House: Blue, Dane, Tea, Horse, Blends
3rd House: Red, Brit, Milk, Birds, Pall Malls
4th House: Green, German, Coffee, FISH, Prince
5th House: White, Swede, Beer, Dogs, Bluemasters Did you answer this riddle correctly?
YES NO
The rest go like this-
1st House: Yellow, Norwegian, Water, Cats, Dunhill
2nd House: Blue, Dane, Tea, Horse, Blends
3rd House: Red, Brit, Milk, Birds, Pall Malls
4th House: Green, German, Coffee, FISH, Prince
5th House: White, Swede, Beer, Dogs, Bluemasters Did you answer this riddle correctly?
YES NO
Who Paid For Dinner?
Wednesday, Tom and Joe went to a restaurant and ate dinner. When they were done they paid for the food and left. But Tom and Joe didn't pay for the food. Who did?
Hint:
A Man Rode Into Town
A man rode into a town with his horse on the 25th of June. He stayed in the town for 3 weeks, then left on June. How is this possible?
Hint:
Dogs At The Market
Hint:
Colorful House Riddle
You can see a beautiful red house on your left and a mesmeric green house on your right, a warming and attractive pink house on your front. Then where is the white house?
Hint:
Not A Single Person Riddle
While walking across a bridge I saw a boat full of people. Yet on the boat there wasn't a single person. Why?
Hint:
Half Of 2+2 Riddle
Hint:
Twelve Pears Riddle
Twelve pears hanging high, twelve men passing by. Each took a pear and left eleven hanging there. How can this be?
Hint:
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