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
Sarah's Seven Apples
A doctor and a bus driver are both in love with the same woman, an attractive girl named Sarah. The bus driver had to go on a long bus trip that would last a week. Before he left, he gave Sarah seven apples. Why?
Hint:
Weight From A Barrel Riddle
Hint:
Murdered On A Sunday Afternoon
Maid: I was fixing the table.
Cook: I was cooking breakfast.
Butler: I was polishing the silverware and the dishes.
Gardener: I was planting tomato seeds.
Wife: I was reading a book.
Who did it?
Hint:
The cook did it. You don't cook breakfast in the afternoon. Did you answer this riddle correctly?
YES NO
YES NO
Tea Cups On The Table
Hint: Try reading the question out loud.
The answer is 3 tea cups because the question was not forty cups it was four tea cups. Did you answer this riddle correctly?
YES NO
YES NO
Coffee Diner Riddle
A man walks into a diner and sits down. There's a new waitress working that he's never seen before. When she comes to his table to take his order, he says "Just a cup of coffee please." A few minutes later the waitress brings the man his coffee and heads back to the kitchen. A short while later, the man notices that there is a fly in his coffee and calls the waitress back. He asks her nicely to bring him another cup. The waitress brings the man's cup of coffee back to the kitchen and returns a few moments later. "Here you are, I poured you a new cup of coffee, no fly this time" she says and hands him the cup. The waitress turns around and starts to head back to the kitchen. She only takes a few steps before she hears the man shout out "Hey, this is the same cup of coffee, all you did was remove the fly!"
Assuming the coffee was still hot, how did the man know it was the same cup of coffee?
Assuming the coffee was still hot, how did the man know it was the same cup of coffee?
Hint: A man walks into a diner and sits down. There's a new waitress working that he's never seen before. When she comes to his table to take his order, he says "Just a cup of coffee please." A few minutes later the waitress brings the man his coffee and heads
Because the coffee was sweet. The man had added sugar to his coffee before noticing the fly. When the waitress brought him the "new" cup of coffee, he took a sip (to check whether it was in fact a newly poured cup of coffee) and noticed that the coffee was "already" sweet. Did you answer this riddle correctly?
YES NO
YES NO
Finding Anna's Picture Riddle
Once upon a time there was a beautiful princess named Anna. Anna's father, the King, wanted to be sure his daughter married an intelligent man. To test his daughter's suitors the King hid Anna's picture in one of three boxes. The suitor had to be able to select the box with Anna's picture on one try and within twenty seconds. On the gold box was the message "Anna's picture is in this box". The silver box had the message "Anna's picture is not in this box." "Anna's picture is not in the gold box" was written on the bronze box. The King would tell each suitor "Only one of the three messages is correct." Which box contained Anna's picture?
Hint:
The silver box contained Anna's picture. If her picture had been in the gold box, two statements would have been true. (The messages on both the gold box and the silver box.) If her picture had been in the bronze box, two statements would have been true. (The messages on the bronze box and the silver box.) Did you answer this riddle correctly?
YES NO
YES NO
Captured By The Riddler
In the land of Geopolizza, three men were captured by the infamous Riddler. So, the Riddler buries the three men, named 1, 2 and 3 in such a manner, that 1 is in the front, 2 in the middle and 3 in the back. They are buried neck deep, and cannot move, not even their heads. He shows them 5 caps, two of which are red and 3 of them are white. He then switches off the lights and places a hat on top of their heads. The situation is such that no one can see their hat color, 1 is facing the wall and cant say anything, 2 can see 1 and 3 can see both 1 and 2. Then he tells the rules of his game: "If either of you three can tell the correct color of your head, I will let all of you go. However, if any of you answer wrong, all 3 of you will instantly die. Time is 3 minutes."
Upon 2 and half minutes passing, A shouts the answer and all 3 are released free. How did he know the correct answer ?
Upon 2 and half minutes passing, A shouts the answer and all 3 are released free. How did he know the correct answer ?
Hint:
P3 can only be certain of his cap if 1 & 2 are both white. Since he is not certain then 1 & 2 must be either white/red or red/red. 2 knows this but the only combination that he will be able to know the colour of his own cap is if he sees that 1 is wearing a white cap. 1 knows this but as 2 remains uncertain then 1 must be wearing a red cap. Did you answer this riddle correctly?
YES NO
YES NO
Running In Circles Riddle
Hint:
Simba's Girlfriend Riddle
Hint:
The Riddle Of Legs
Hint:
The answer to all three is a baby. True, it crawls on all fours, but cut off its legs and it can only wiggle on two limbs. Give it a crutch, it can hobble around on three. Did you answer this riddle correctly?
YES NO
YES NO
The Riddle Of Gestumblindi Scandinavia
Four hang, four sprang, two point the way, two to ward off dogs, one dangles after, always rather dirty. What am I?
Hint:
Written In Blood Riddle
On a dark, stormy Halloween night, four kids named Luke, John, Sarah and Bob walk into a haunted house during a blackout. Only one can escape. They take a staircase to the second floor, a trapdoor on the left, then go up the ladder to the right, followed by a 28-foot slide to the basement through the mouth of a Giant Panda. In one corner of the murky cellar is a chainsaw, a dagger, a rope with a noose and an electric chair. Written on the wall in blood are the words, Only one will survive choose your death! Bob takes the rope, Sarah picks up the dagger, John chooses the chainsaw and Luke uses the chair.
Who survives?
Who survives?
Hint:
The House Of Seeing
Hint:
There is a house. One enters it blind and leaves it seeing. What is it? Did you answer this riddle correctly?
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YES NO
Locked In A Room
Rooney was locked in a room by kidnappers.
All that is in the room is a piano, calendar, and a bed. The room is locked from the outside.
What does he eat, drink, and how does he escape and get out?
All that is in the room is a piano, calendar, and a bed. The room is locked from the outside.
What does he eat, drink, and how does he escape and get out?
Hint:
Rooney eats the 'dates' on the calendar, gets water from the waterbed, and uses the piano key to escape. Did you answer this riddle correctly?
YES NO
YES NO
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