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 Prime Number Riddle
Two hundred people in an auditorium are asked to think of a single digit number from 1 to 9 inclusive and write it down. All those who wrote down a prime number are now asked to leave. Ninety people remain behind in the hall. How many of these are expected to have written down an odd number?
Hint: Remember that 1 is not a prime number.
Those that remain behind must have written {1,4,6,8,9} and from this only {1,9} are odd. The probability of an odd number is thus 2/5.
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
A Man Was Outside Taking A Walk When It Began To Rain
A man was outside taking a walk when it began to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?
Hint:
9 Letters Riddle
What word in English has 9 letters that keeps producing another word when you remove any one letter from it (goes on up to a single letter)?
Hint:
Startling - starting - staring - string - sting - sing - sin - in - I. Did you answer this riddle correctly?
YES NO
YES NO
Christmas Vehicular Homicide Riddle
Vehicular homicide was committed on Dad's mom by a precipitous darlin, what Christmas Carol is this?
Hint:
A Girl Unlocks Her Boyfriend's Phone Riddle
A girl unlocks her boyfriend's phone. She found three different contacts having the same name "LOVE". 1st "Love" is the daughter of his dad's dad daughter in law. 2nd "Love" is the mother of his mother and 3rd one is she herself.
Hows the 1st contact is related to the 2nd one?
Hows the 1st contact is related to the 2nd one?
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:
There Was A Plane Crash Riddle
Hint:
17 Cows Riddle
An old farmer died and left 17 cows to his three sons. In his will, the farmer stated that his oldest son should get 1/2, his middle son should get 1/3, and his youngest son should get 1/9 of all the cows. The sons, who did not want to end up with half cows, sat for days trying to figure out how many cows each of them should get.
One day, their neighbor came by to see how they were doing after their father's death. The three sons told him their problem. After thinking for a while, the neighbor said: "I'll be right back!" He went away, and when he came back, the three sons could divide the cows according to their father's will, and in such a way that each of them got a whole number of cows.
What was the neighbor's solution?
One day, their neighbor came by to see how they were doing after their father's death. The three sons told him their problem. After thinking for a while, the neighbor said: "I'll be right back!" He went away, and when he came back, the three sons could divide the cows according to their father's will, and in such a way that each of them got a whole number of cows.
What was the neighbor's solution?
Hint:
The neighbour borrowed an extra cow, to make the total number of cows 18. Then the oldest son got 1/2 of 18 is 9 cows, the middle son got 1/3 of 18 is 6 cows, and the youngest son got 1/9 of 18 is 2 cows. Since 9+6+2 = 17, the cows could be divided among the three brothers in such a way that the borrowed cow was left over, and could be returned to its owner. Did you answer this riddle correctly?
YES NO
YES NO
Fox Goose Beans Riddle
Once upon a time a farmer went to a market and purchased a fox, a goose, and a bag of beans. On his way home, the farmer came to the bank of a river and rented a boat. But in crossing the river by boat, the farmer could carry only himself and a single one of his purchases: the fox, the goose, or the bag of beans. If left unattended together, the fox would eat the goose, or the goose would eat the beans. The farmer's challenge was to carry himself and his purchases to the far bank of the river, leaving each purchase intact. How did he do it?
Hint:
The first step must be to take the goose across the river, as any other will result in the goose or the beans being eaten. When the farmer returns to the original side, he has the choice of taking either the fox or the beans across next. If he takes the fox across, he would have to return to get the beans, resulting in the fox eating the goose. If he takes the beans across second, he will need to return to get the fox, resulting in the beans being eaten by the goose. The dilemma is solved by taking the fox (or the beans) over and bringing the goose back. Now he can take the beans (or the fox) over, and finally return to fetch the goose. His actions in the solution are summarized in the following steps: Take the Goose over Return Take the beans over Return with the goose Take the fox over Return Take goose over Thus there are seven crossings, four forward and three back. Did you answer this riddle correctly?
YES NO
YES NO
$97 Shirt Riddle
I saw a shirt for $97. I borrowed $50 from Mom and $50 from Dad. I bought the shirt with $3 of change. I gave $1 to Mom, $1 to Dad, and kept $1 for myself. Now I owe my mom $49 and my dad $49. $49 + $49 = $98 + my $1 = $99. Where did the other $1 go?
Hint:
The two $49 figures mentioned in the riddle? Those are inconsequential for actually solving it - they're the debt this fashionable shopper owes his or her parents, not the money that actually changed hands during any of the transactions. So, in truth, the dollar didn't "go" anywhere; it's been there all along. You just have to know where to look for it - and what not to be distracted by. Did you answer this riddle correctly?
YES NO
YES NO
If Lupitas Daughter Riddle
Lupita's dad has 5 daughters, Lisa, Laura, Liza and Lolo. What is the name of the other daughter missing?
Hint:
The answer to 'If Lupita's dad's daughter' riddle is Lupita herself. The key to this simple riddle is the very first line of the riddle. In the first line of this riddle, it is stated that "Lupita's dad has 5 daughters".
In the subsequent list, "Lisa, Laura, Liza and Lolo," Lupita's name is missing. When the final part of the riddle asks who the fifth daughter is, some people get confused and think that the answer is in the last part itself.
However, if one pays attention, then they will immediately realize that the list is about Lupita's dad's daughters. Hence Lupita herself is the name missed out from the list. Its all just wordplay, but anyone can be tricked if they do not pay attention to the nuances of the riddle. Did you answer this riddle correctly?
YES NO
In the subsequent list, "Lisa, Laura, Liza and Lolo," Lupita's name is missing. When the final part of the riddle asks who the fifth daughter is, some people get confused and think that the answer is in the last part itself.
However, if one pays attention, then they will immediately realize that the list is about Lupita's dad's daughters. Hence Lupita herself is the name missed out from the list. Its all just wordplay, but anyone can be tricked if they do not pay attention to the nuances of the riddle. Did you answer this riddle correctly?
YES NO
I Had 3.00 Riddle
I had $3.00. My mom gave me $10.00 while my dad gave me $30.00. My aunt and uncle gave me $100.00. I had another $5.00. How much did I have?
Hint:
The correct answer is 8 dollars. If you read the question carefully, the question asked about your first money with "how much money Did I really have?"
The money you had is 10 dollars. That is before your parents and relatives gave you additional money.
However, given that the logic and time of the tense is in the past, it is safe to assume that the question pertains to the money you had originally before you received external money from someone else. Did you answer this riddle correctly?
YES NO
The money you had is 10 dollars. That is before your parents and relatives gave you additional money.
However, given that the logic and time of the tense is in the past, it is safe to assume that the question pertains to the money you had originally before you received external money from someone else. Did you answer this riddle correctly?
YES NO
I Had 5 Pesos Riddle
I had 5 pesos. My mom gives me 10 pesos, while my dad gave me 30 pesos. My aunt and uncle give 100 pesos. I had another 5 pesos. How much money did I really have?
Hint:
The correct answer is 10 pesos. If you read the question carefully, the question asked about your first money with "how much money DID I really have?" The money you had is 10 pesos. That is before your parents and relatives gave you additional money. However, given that the logic and time of the tense is in the past, it is safe to assume that the question pertains to the money you had originally before you received external money from someone else. Therefore, you had 5 pesos and another 5 pesos originally with you, which sums up to 10 pesos. Did you answer this riddle correctly?
YES NO
YES NO
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