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:
Men Before Women Riddle
Hint:
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:
Four Days Of School Riddle
A student has missed an excessive number of days at school and thus the principal called him to his office and requested for an explanation.
The student said, There just isnt enough time for school. I need 8 hours of sleep a day, which adds up to about 122 days a year. Weekends off is 104 days a year. Summer vacation is about 60 days. If I spend about an hour on each meal, thats 3 hours a day or 45 days a year. I need at least 2 hours of exercise and relaxation time each day to stay physically and mentally fit, adding another 30 days.
Add all of that up and you get about 361 days. That only leaves 4 days for school.
The principal is confused, but cant figure out why. What is wrong with the students argument?
The student said, There just isnt enough time for school. I need 8 hours of sleep a day, which adds up to about 122 days a year. Weekends off is 104 days a year. Summer vacation is about 60 days. If I spend about an hour on each meal, thats 3 hours a day or 45 days a year. I need at least 2 hours of exercise and relaxation time each day to stay physically and mentally fit, adding another 30 days.
Add all of that up and you get about 361 days. That only leaves 4 days for school.
The principal is confused, but cant figure out why. What is wrong with the students argument?
Hint:
The student is double counting a lot of the days. A lot of the time spent sleeping, eating, and relaxing occurs during weekends and the summer. Weekends also occur during the summer, so all of these hours are getting counted several times.
And, school is not an all day affair. So the 4 days actually represents more days of school. If school is 6 hours per day, those four days represents 16 days of school. Did you answer this riddle correctly?
YES NO
And, school is not an all day affair. So the 4 days actually represents more days of school. If school is 6 hours per day, those four days represents 16 days of school. Did you answer this riddle correctly?
YES NO
100 Billion Neurons Riddle
Hint:
The Pizza Business Riddle
Hint:
Hit By A Bus Riddle
A man walks into a restaurant, orders albatross, takes one bite of the meal, runs out into the street and is hit by a bus. Why?
Hint:
The man had been on a cruise with his wife. They had shipwrecked on a deserted island, and the mans wife had died. The people on the island were starving. One day the people brought some food to the man, saying that it was an albatross they had shot. When the man went to the restaurant and tasted the albatross, he realized that what he had eaten before must not have been albatross at all. He realized that he had likely eaten his wife. The thought made him so upset that he dashed out into the road without looking for traffic. Did you answer this riddle correctly?
YES NO
YES NO
108 Spiders Riddle
Hint:
A Golden Treasure Riddle
A golden treasure that never stays;
The coin whose face gives wealth to all.
Strands, nuggets, and dust of gold
are all bought with its shining grace...
And all are more precious than any gleaming metal.
What am I?
The coin whose face gives wealth to all.
Strands, nuggets, and dust of gold
are all bought with its shining grace...
And all are more precious than any gleaming metal.
What am I?
Hint:
100 Politicians Riddle
There is a party of 100 high-powered politicians. All of them are either honest or liars. You walk in knowing two things:
- At least one of them is honest.
- If you take any two politicians, at least one of them is a liar.
From this information, can you know how many are liars and how many are honest?
- At least one of them is honest.
- If you take any two politicians, at least one of them is a liar.
From this information, can you know how many are liars and how many are honest?
Hint:
Yes, from the information you know 1 is honest and 99 are liars.
One of them is honest satisfying the first piece of information. Then if you take the honest man and any other politician, the other politician must be a liar to satisfy the second piece of information, 'If you take any two politicians, at least one of them is a liar.' So 99 are liars. Did you answer this riddle correctly?
YES NO
One of them is honest satisfying the first piece of information. Then if you take the honest man and any other politician, the other politician must be a liar to satisfy the second piece of information, 'If you take any two politicians, at least one of them is a liar.' So 99 are liars. Did you answer this riddle correctly?
YES NO
100 Year Old Ant Riddle
Hint:
Adding To 1000 Riddle
Do this in your head don't use paper and pencil or a calculator just your mind.
Take 1000 and add 40. Now add 1000, add 30,add 1000, add 20, add 1000, add 10
what is your answer?
Take 1000 and add 40. Now add 1000, add 30,add 1000, add 20, add 1000, add 10
what is your answer?
Hint:
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