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
A Pet With Four Legs Riddle
Im a pet that has four legs
And a tail at the end
You might hear me barking
And Im known as mans best friend
What am I?
And a tail at the end
You might hear me barking
And Im known as mans best friend
What am I?
Hint:
Fifty One Bicycles
Hint:
The man was playing a poker game and cheated. The bicycles are a type of card. Did you answer this riddle correctly?
YES NO
YES NO
Couples Climbing Trip Riddle
A couple went on a climbing trip. But only the husband returned from the vacation and said that his wife slipped off while climbing and died. After investigating, the local sheriff arrested him saying, Your travel agent called. You murdered your wife.
The man did not inform anyone about the trip. So how was the agent so sure that it is a murder?
The man did not inform anyone about the trip. So how was the agent so sure that it is a murder?
Hint:
The man bought only a one way ticket for his wife whereas he bought a two way ticket for himself. He was certain he would return alone. Did you answer this riddle correctly?
YES NO
YES NO
Shot In The Car Riddle
A man was shot to death while in his car. There were no powder marks on his clothing, which indicated that the gunman was outside the car. However, all the windows were up and the doors locked. After a close inspection was made, the only bullet-holes discovered were on the mans body. How was he murdered?
Hint:
The victim was in a convertible. He was shot when the top was down. Did you answer this riddle correctly?
YES NO
YES NO
Footprints Between Two Parallel Lines Riddle
Hint:
The Scene Of The Crime Riddle
A man murders his wife with a knife in their car. Nobody is around to see this. He throws her out of the car being careful not to leave any fingerprints on her body. Next he throws the knife off of a cliff into a valley where it will never be found and he goes home. An hour later the police call him and tell him that his wife has been murdered and he needs to come to the scene of the crime immediately. As soon as he arrives, he is arrested.
Hint:
The police did not tell him the location of the crime scene but he arrived at the correct place. Did you answer this riddle correctly?
YES NO
YES NO
Today's Bar Special Riddle
A man walks into a bar and says: Give me today's special. The bartender says: In a shot or a bottle? The man says: In a shot. The bartender gives it to him. He drinks it and then he dies. Why did he die?
Hint:
Building A Bar Riddle
Roy Smith wanted a new bar. He was such an eccentric old bar owner that he wanted a bar in which all fours walls faced south. After much thought, the builders managed to construct just such a bar. How did they do it?
Hint:
The Murder At Joe's Riddle
Some one was murdered at Joes Bar & Grill on a Sunday afternoon. The police interviewed the suspects and got their alibis. They were:
Cook: was cutting celery
Manager: was getting mail
Bartender: was filling the beer cooler
Cocktail waitress: was cutting fruit
Paul the regular: was reading the paper
The police arrested the murderer with no problem at all.
Who was the murder and how did the police know so easily?
Cook: was cutting celery
Manager: was getting mail
Bartender: was filling the beer cooler
Cocktail waitress: was cutting fruit
Paul the regular: was reading the paper
The police arrested the murderer with no problem at all.
Who was the murder and how did the police know so easily?
Hint:
It was the manager because the mail does not come on Sundays. Did you answer this riddle correctly?
YES NO
YES NO
Alone In The Woods Riddle
Hint:
A Complicated Coop Riddle
There was a farmer and he had a problem with his coop (the place where you keep the birds), and he wanted to go check it out. When he got there he noticed that there was a rooster on the barn. Now the barn was shaped with a triangle type top. But suddenly the rooster laid an egg. Which side did it roll on?
Hint:
How Many Birth Days Riddle
Hint:
One, he may have many Birthdays, but only one birth day. Did you answer this riddle correctly?
YES NO
YES NO
Who Stole The Money Riddle
A man placed a $100 dollar bill on his desk and left for work. When he returned back the money was gone. He has three suspects: the cook, the maid and the electrician.
The cook said he put the bill under a book on his desk to keep it safe. The man checked and it is no longer there.
The maid said she moved the bill to the inside of the book between page 1 and 2 while she was cleaning. Again, the man checked the book and there was nothing between page 1 and 2.
The electrician said he saw the bill sticking out of the book and he moved it between page 2 and 3 to keep it safe.
Who stole the money?
The cook said he put the bill under a book on his desk to keep it safe. The man checked and it is no longer there.
The maid said she moved the bill to the inside of the book between page 1 and 2 while she was cleaning. Again, the man checked the book and there was nothing between page 1 and 2.
The electrician said he saw the bill sticking out of the book and he moved it between page 2 and 3 to keep it safe.
Who stole the money?
Hint:
The electrician stole the money.
If the man checked for the money between page 1 and 2 of the book, then page 2 and 3 will be opposite sides of a single page and will not be able to hold the money.
Did you answer this riddle correctly?
YES NO
If the man checked for the money between page 1 and 2 of the book, then page 2 and 3 will be opposite sides of a single page and will not be able to hold the money.
Did you answer this riddle correctly?
YES NO
Anonymous Phone Call Riddle
Acting on an anonymous phone call, the police raid a house to arrest a suspected murderer. They dont know what he looks like but they know his name is John and that he is inside the house. The police bust in on a carpenter, a lorry driver, a mechanic and a fireman playing cards. Without hesitation or communication of any kind, they immediately arrest the fireman. How do they know theyve got their man?
Hint:
The fireman is the only man in the room. The rest of them are women. Did you answer this riddle correctly?
YES NO
YES NO
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