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 Traffic Light Riddle
There is a traffic light at the top of a hill. Cars can't see the light until they are 200 feet from the light.
The cycle of the traffic light is 30 seconds green, 5 seconds yellow and 20 seconds red.
A car is traveling 45 miles per hour up the hill.
What is the probability that the light will be yellow when the driver first crests the hill and that if the driver continues through the intersection at her present speed that she will run a red light?
The cycle of the traffic light is 30 seconds green, 5 seconds yellow and 20 seconds red.
A car is traveling 45 miles per hour up the hill.
What is the probability that the light will be yellow when the driver first crests the hill and that if the driver continues through the intersection at her present speed that she will run a red light?
Hint:
The probability of the driver encountering a yellow light and the light turning red before the car enters the intersection is about 5.5%.
At 45 mph the car is traveling at 66 feet/second and will take just over 3 seconds (3.03) to travel the 200 feet to the intersection. Any yellow light that is in the last 3.03 seconds of the light will cause the driver to run a red light.
The entire cycle of the light is 55 seconds. 3.03/55 = 5.5%. Did you answer this riddle correctly?
YES NO
At 45 mph the car is traveling at 66 feet/second and will take just over 3 seconds (3.03) to travel the 200 feet to the intersection. Any yellow light that is in the last 3.03 seconds of the light will cause the driver to run a red light.
The entire cycle of the light is 55 seconds. 3.03/55 = 5.5%. Did you answer this riddle correctly?
YES NO
Billie's Birthday Riddle
Billie was born on December 28th, yet her birthday always falls in the summer. How is this possible?
Hint:
Helping You Move Riddle
Im something that helps you move
But I am not a wheel
As Im part of your body
With a sole and a heel
What are they
But I am not a wheel
As Im part of your body
With a sole and a heel
What are they
Hint:
Ligaments Connect Riddle
You will find 206
Inside adult human bodies
Together theyre a skeleton
Ligaments connect all of these
They are?
Inside adult human bodies
Together theyre a skeleton
Ligaments connect all of these
They are?
Hint:
Over London Bridge
As I went over London Bridge
I met my sister Jenny
I broke her neck and drank her blood
And left her standing empty
Who is Jenny?
I met my sister Jenny
I broke her neck and drank her blood
And left her standing empty
Who is Jenny?
Hint:
Emoji Balloon Riddle
Hint: Its a song
Caramel Macchiato Riddle
Hint:
Banana Clock Riddle
Hint: 1. Look closely at the clock.
2. Number of Bananas.
3. Some thing regarding the sides of the Shapes figure.
38
Logic :
From 1st the hexagon shape has value 15.
The shape has 15 edges(6 of hexagon,5 of Pentagon and 4 of Square)
From 2nd we get value of one bunch of bananas is 4.
So each banana has value of 1.
From 3rd we get that each clock has value of 3.
Which resembles the time on the clock which is 3.
Hence by using these insights, we get the last required values as
Clock = 2 (2 in the clock)
Bananas = 3 (3 bananas in the bunch)
Hexagon = 11 (Hexagon[6 sides] and pentagon[5 sides], so 6+5=11)
So required value is
2+3+3x11=?
2+3+33=? (Multiply first - Bodmas rule)
5+33=38 and hence the answer is 38. Did you answer this riddle correctly?
YES NO
Logic :
From 1st the hexagon shape has value 15.
The shape has 15 edges(6 of hexagon,5 of Pentagon and 4 of Square)
From 2nd we get value of one bunch of bananas is 4.
So each banana has value of 1.
From 3rd we get that each clock has value of 3.
Which resembles the time on the clock which is 3.
Hence by using these insights, we get the last required values as
Clock = 2 (2 in the clock)
Bananas = 3 (3 bananas in the bunch)
Hexagon = 11 (Hexagon[6 sides] and pentagon[5 sides], so 6+5=11)
So required value is
2+3+3x11=?
2+3+33=? (Multiply first - Bodmas rule)
5+33=38 and hence the answer is 38. Did you answer this riddle correctly?
YES NO
Failed Salute Riddle
Why did 2nd lieutenant Hasley salute Captain Longley, but neglect to salute the other higher ranking officers that he passed in the hallway?
Hint:
Saluting indoors is forbidden except when formally reporting to a superior officer. Did you answer this riddle correctly?
YES NO
YES NO
What Can You Hold In Your Right Hand Riddle
Hint:
Running A Race And Passed The Person In Second Place
Hint:
Shoe Man Whistle
Hint:
The third equation has a term with a pair of whistles. The last line involves a single whistle.
Furthermore, the man in the second and third lines are wearing a whistle, but the man in the last line is not wearing a whistle. Presumably the value of the whistle should be accounted for to get the correct answer.
The pictures can be translated into the following equations:
shoes + shoes + shoes = 30
shoes + (man + whistle) + (man + whistle) = 20
(man + whistle) + 2(whistles) + 2(whistles) = 13
shoes + (man) x (whistle) = ?
From the first equation we can solve for the shoes value:
shoes + shoes + shoes = 30
3(shoes) = 30
shoes = 10
We can then solve the second equation for the (man + whistle) value:
shoes + (man + whistle) + (man + whistle) = 20
10 + 2(man + whistle) = 20
2(man + whistle) = 10
man + whistle = 5
Then we solve the third equation for the whistle:
(man + whistle) + 2(whistles) + 2(whistles) = 13
5 + 4(whistles) = 13
4(whistles) = 8
whistle = 2
We also need to solve for the value of the man:
man + whistle = 5
man + 2 = 5
man = 3
Now we can evaluate the final expression, remembering the order of operations that multiplication should be evaluated before addition:
shoes + (man) x (whistle) = ?
10 + 3 x 2
= 10 + 3 x 2
= 10 + 6
= 16 Did you answer this riddle correctly?
YES NO
Furthermore, the man in the second and third lines are wearing a whistle, but the man in the last line is not wearing a whistle. Presumably the value of the whistle should be accounted for to get the correct answer.
The pictures can be translated into the following equations:
shoes + shoes + shoes = 30
shoes + (man + whistle) + (man + whistle) = 20
(man + whistle) + 2(whistles) + 2(whistles) = 13
shoes + (man) x (whistle) = ?
From the first equation we can solve for the shoes value:
shoes + shoes + shoes = 30
3(shoes) = 30
shoes = 10
We can then solve the second equation for the (man + whistle) value:
shoes + (man + whistle) + (man + whistle) = 20
10 + 2(man + whistle) = 20
2(man + whistle) = 10
man + whistle = 5
Then we solve the third equation for the whistle:
(man + whistle) + 2(whistles) + 2(whistles) = 13
5 + 4(whistles) = 13
4(whistles) = 8
whistle = 2
We also need to solve for the value of the man:
man + whistle = 5
man + 2 = 5
man = 3
Now we can evaluate the final expression, remembering the order of operations that multiplication should be evaluated before addition:
shoes + (man) x (whistle) = ?
10 + 3 x 2
= 10 + 3 x 2
= 10 + 6
= 16 Did you answer this riddle correctly?
YES NO
7 Ice Cubes Riddle
I have 7 ice cubes inside a cup of water how many ice cubes do I have left after putting the cup in the freezer?
Hint:
$100 Bill Grocery Store Thief
A guy walks into a store and steals a $100 bill from the register without the owners knowledge.
He then buys $70 worth of goods using the $100 bill and the owner gives $30 in change.
How much money did the owner lose?
$30, $70, $100, $130, $170, or $200?
He then buys $70 worth of goods using the $100 bill and the owner gives $30 in change.
How much money did the owner lose?
$30, $70, $100, $130, $170, or $200?
Hint:
The best answer from the choices is the owner lost $100. The $100 bill that was stolen was then given back to the owner. What the owner loses is the $70 worth of goods and the $30 in change, which makes for a total of $70 + $30 = $100. The owner has lost $100.
Technically, the owner lost $30 plus the value, V, of the $70 of goods. Since stores typically sell goods at a markup, the value may be less than $70. But in the case of a loss leader, the owner may have lost more than $70. Did you answer this riddle correctly?
YES NO
Technically, the owner lost $30 plus the value, V, of the $70 of goods. Since stores typically sell goods at a markup, the value may be less than $70. But in the case of a loss leader, the owner may have lost more than $70. Did you answer this riddle correctly?
YES NO
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