The 100 Seat Airplane
People are waiting in line to board a 100-seat airplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise they will choose an open seat at random to sit in.
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
Hint: You don't need to use complex math to solve this riddle. Consider these two questions:
What happens if somebody sits in your seat?
What happens if somebody sits in Steve's assigned seat?
The correct answer is 1/2.
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
Chocolate All Year Long
Hint:
A Lions Appetite Riddle
Hint:
20 Apples Riddle
There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?
Hint:
Between The Pages Riddle
Jack tells Jill, "This isn't the $5 bill you left on the the table. I found it between pages 15 and 16 of Harry Potter."
Jill retorts, "You're lying and I can prove it." How did Jill know?
Jill retorts, "You're lying and I can prove it." How did Jill know?
Hint:
Harry Potter, like all other books, has odd-numbered pages on the right. Therefore, pages 15 and 16 are the front and back of a single page, and nothing could have been found between them. Did you answer this riddle correctly?
YES NO
YES NO
It Was Murder Riddle
A body is found at the bottom of a multistory building. Seeing the position of the body it is evident that the person jumped from one of the windows.
A homicide detective is called to look after the case. He goes to the first floor and walks in the room facing the direction in which the body was found. He opens the window in that direction and flips a coin towards the floor.
Then he goes to the second floor and repeats the process. He keeps on doing it till the last floor. Then, when he climbs down, he tells the team that it is a murder not suicide.
How did he come to know that it was a murder?
A homicide detective is called to look after the case. He goes to the first floor and walks in the room facing the direction in which the body was found. He opens the window in that direction and flips a coin towards the floor.
Then he goes to the second floor and repeats the process. He keeps on doing it till the last floor. Then, when he climbs down, he tells the team that it is a murder not suicide.
How did he come to know that it was a murder?
Hint:
At each floor, he did the same task of opening the window and flipping the coin. If it was a suicide, then at least the window at any of the floors must have been left open by the person who jumped off. The situation only suggests that someone pushed him off and then closed the window again. Did you answer this riddle correctly?
YES NO
YES NO
World War 1 Riddle
A grandfather is telling his grandson war stories.
At the end of World War 1, I was awarded for my bravery after saving a group of my men, the grandfather says. You see, we were fighting in northern France and one of our enemies threw a grenade at us. I managed to pick it up and throw it away before it exploded. So right after the war ended, a General gave me a sword, engraved with the words Awarded for Bravery and Valor, A True Hero, World War 1.
The grandson thinks about the story for a minute and then says Grandpa, that story can't be true! How did the grandson know?
At the end of World War 1, I was awarded for my bravery after saving a group of my men, the grandfather says. You see, we were fighting in northern France and one of our enemies threw a grenade at us. I managed to pick it up and throw it away before it exploded. So right after the war ended, a General gave me a sword, engraved with the words Awarded for Bravery and Valor, A True Hero, World War 1.
The grandson thinks about the story for a minute and then says Grandpa, that story can't be true! How did the grandson know?
Hint:
It was the only World War at that time and World War 2 had not started yet. Did you answer this riddle correctly?
YES NO
YES NO
Cabin On The Mountain Riddle
There is a cabin on the side of a mountain. Three people are inside and they are dead. How did they die?
Hint:
They were killed in a plane crash The three people were the pilot, co-pilot, and navigator. They crashed in snow storm. Did you answer this riddle correctly?
YES NO
YES NO
A Man In The Shadows Riddle
Hint:
Breakfast And Tea Riddle
People can sell me, yet I have many clones.
I can bring you laughter between breakfast and tea,
Yet I can also break your heart easily.
I cover the earth like trees of old,
Whose leaves can blind and yet enfold.
Hint:
A book. Authors can speak to you through a book, yet the book makes no sound. Books are sold and have many duplicate copies. A book can bring the reader to tears and laughter, they span the globe and the leaves of a book (a single sheet in a book is called a leaf) can get you wrapped up in the story that youre unaware of whats going on around you. Did you answer this riddle correctly?
YES NO
YES NO
Driven Through The Day Riddle
People are driven through the day by me
Late nights I do inspire
If not contained I run wild
What am I?
Late nights I do inspire
If not contained I run wild
What am I?
Hint:
The Bus Stop Riddle
An empty bus pulls up at a stop and 5 people get on. At the next stop 5 people get off and twice as many people get on as at the first stop. At the third stop 10 people get off.
How many people are on the bus at this point?
How many people are on the bus at this point?
Hint:
Ne, the bus driver.
On the 1st stop, 5 people get on. On the 2nd stop, 5 people get off and 10 (twice as many as at 1st stop) people get on. On the 3rd stop, 10 people get off. So there are (5 5 + 10 10) 0 passengers left, which leaves the bus driver as the only person on board the bus. Did you answer this riddle correctly?
YES NO
On the 1st stop, 5 people get on. On the 2nd stop, 5 people get off and 10 (twice as many as at 1st stop) people get on. On the 3rd stop, 10 people get off. So there are (5 5 + 10 10) 0 passengers left, which leaves the bus driver as the only person on board the bus. Did you answer this riddle correctly?
YES NO
From Block To Block Riddle
I carry lots of people.
I pick them up and drop them off.
I might travel from city to city.
I might only go from block to block.
I am a...
I pick them up and drop them off.
I might travel from city to city.
I might only go from block to block.
I am a...
Hint:
Rings Tell My Age Riddle
Hint:
Saturn Has Them Riddle
Saturn has them. Married people wear them. A tree's age can be determined by counting them. What is it?
Hint:
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