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
Three People At A Bus Stop Riddle
You're driving down the road in your car on a wild and stormy night. The weather is like a hurricane, with heavy rains, high winds, and lightning flashing constantly. While driving, you come across a partially-covered bus stop, and you can see three people waiting for a bus:
1. An old woman who looks as if she is about to die.
2. An old friend who once saved your life.
3.The perfect partner you have been dreaming about (your soulmate).
Knowing that you only have room for one passenger in your car (its a really small car), which one would you choose to offer a ride to? And why?
1. An old woman who looks as if she is about to die.
2. An old friend who once saved your life.
3.The perfect partner you have been dreaming about (your soulmate).
Knowing that you only have room for one passenger in your car (its a really small car), which one would you choose to offer a ride to? And why?
Hint:
I would give the car keys to my old friend, and let him take the old woman to the hospital. Then I would stay behind and wait for the bus with the partner of my dreams. Did you answer this riddle correctly?
YES NO
YES NO
I Have Seas Without Water Riddle
I have seas without water, coast without sand, towns without people, mountains without land. What am I?
Hint:
How Many People?
Hint:
9. Two twins are 2 people, three triplets are 3 people, and four quadruplets are 4 people. 2 + 3 + 4 = 9. Did you answer this riddle correctly?
YES NO
YES NO
Find That Tennis Ball
You have 7 tennis balls that are all identical but one of them is slightly lighter than the others.
Using a balance scale and only two separate weightings, how can you find the light tennis ball?
Using a balance scale and only two separate weightings, how can you find the light tennis ball?
Hint:
Put three of the balls on each side. If they are even the ball that wasn't weighed is the light one. If they aren't even the side that is lighter has the light ball. Of these three balls, one should be put on each side. If the sides are even than the other ball is the light one. If they aren't even the one that is lighter is the ball you're looking for. Did you answer this riddle correctly?
YES NO
YES NO
Seagulls In The Sea
Hint:
Because if they flew over the bay they would be called bagels! Did you answer this riddle correctly?
YES NO
YES NO
Trampoline Season
Hint:
Football Banking Riddle
Hint:
Fasten Two People
I fasten two people, while touching only one. It is love I represent, in a forever that has just begun.
Hint:
Find Me In The Classroom Riddle
I have two hands. I have a face.
My hands go round and round.
I have the numbers 1 to 12
Instead of smiles and frowns.
Find me in the classroom.
What am I?
My hands go round and round.
I have the numbers 1 to 12
Instead of smiles and frowns.
Find me in the classroom.
What am I?
Hint:
Over 1,000 People Went Down Riddle
Over 1,000 people went down on me. I wasnt a maiden for long. Something really big and hard ripped me open. What am I?
Hint:
The Red Sea Riddle
Hint:
The Black Sea Riddle
Hint:
Chicken At The Seance Riddle
Hint:
The Sea's Blue Skirt Riddle
Hint:
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