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
Add Up To 100 Riddle
With the numbers 123456789, make them add up to 100. They must stay in the same order. You can use addition, subtraction, multiplication, and division. Remember, they have to stay in the same order!
Hint:
The Left Side Of The Cake
Hint:
Left On A Bus Riddle
One night, a king and a queen got on a bus with no bus driver. The king and a queen got off the bus. Who is left on the bus?
Hint:
Abandoned Aquarium Riddle
There is an abandoned aquarium in an empty house. The aquarium has three large fish and three small fish. But after a week, one large fish and two small fish die.
How many remain in the aquarium?
How many remain in the aquarium?
Hint:
Six Foot Fishing Pole Riddle
A boy goes and buys a fishing pole that is 6 3 long. As he goes to get on the bus, the bus driver tells him that he cant take anything on the bus longer than 6. The boy goes back to town, buys one more thing, and the bus driver allows him on the bus. What did he buy and what did he do with it?
Hint:
100 Widgets Riddle
Hint:
It would take 5 minutes. Each machine takes 5 minutes to make its widget. Therefore, each of the 100 machines would have finished making its widget in 5 minutes. Did you answer this riddle correctly?
YES NO
YES NO
100 Meter Sprint Riddle
Hint:
100 Lawyers Riddle
Hint:
Less Than 100 Riddle
Find a number less than 100 that is increased by one-fifth of its value when its digits are reversed.
Hint:
I Will Die Riddle
Hint:
Escaping The Estranged Island
You wake up on an estranged island. You look everywhere and you find nothing. You search everywhere on the island and finally come across three torn pieces that can be joined to make one.
How will you escape the island using those torn pieces of paper?
PS: You have no other resources and you can't build anything of your own.
How will you escape the island using those torn pieces of paper?
PS: You have no other resources and you can't build anything of your own.
Hint:
Nothing is the name of a boat that has been lying docked up to one corner of the island. You found it first and then the torn pieces of paper reviled a map that can be used to navigate while driving that ship. Thus using them, you will be able to make an escape. Did you answer this riddle correctly?
YES NO
YES NO
Left And Right Brain Riddle
Hint:
100 Billion Neurons Riddle
Hint:
The 100th Floor Riddle
A man lives on the 100th floor of his apartment building. Every day he takes the elevator down from his apartment to the lobby. After work, he takes the elevator from the lobby to the 50th floor and walks up the stairs the rest of the way. On rainy days he takes the elevator all the way from the lobby to the 100th floor. Why?
Hint:
The man was a dwarf. On rainy days he had an umbrella to help him press the button 100. Did you answer this riddle correctly?
YES NO
YES NO
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