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
It Was Murder Riddle
A body is found at the bottom of a multistory building. Seeing the position of the body it is evident that the person jumped from one of the windows.
A homicide detective is called to look after the case. He goes to the first floor and walks in the room facing the direction in which the body was found. He opens the window in that direction and flips a coin towards the floor.
Then he goes to the second floor and repeats the process. He keeps on doing it till the last floor. Then, when he climbs down, he tells the team that it is a murder not suicide.
How did he come to know that it was a murder?
A homicide detective is called to look after the case. He goes to the first floor and walks in the room facing the direction in which the body was found. He opens the window in that direction and flips a coin towards the floor.
Then he goes to the second floor and repeats the process. He keeps on doing it till the last floor. Then, when he climbs down, he tells the team that it is a murder not suicide.
How did he come to know that it was a murder?
Hint:
At each floor, he did the same task of opening the window and flipping the coin. If it was a suicide, then at least the window at any of the floors must have been left open by the person who jumped off. The situation only suggests that someone pushed him off and then closed the window again. Did you answer this riddle correctly?
YES NO
YES NO
Ida's Microwaved Coffee Riddle
Ida puts her coffee into the microwave, as she does every morning, for exactly two minutes. When the microwave goes off, she opens the door, but then closes the door again and sets the microwave for two more seconds. What good would two more seconds be?
Hint:
To rotate the handle on the mug so she can comfortably remove it. Did you answer this riddle correctly?
YES NO
YES NO
Vampire Savings Riddle
Hint:
The Detective Trap Riddle
Detective Sara Dunts was called in for an investigation on a Saturday morning. Mr. John Gooding had mysteriously vanished from his one story home, Sara was told. "I'll phone Mrs. Glen, the caretaker, and get you the address." Detective Chad Sandlers, Sara's partner, said. Sara stood waiting as he made the call. "Okay, everything's set. Mrs. Glen will be expecting you in half an hour at 232 Parker At." Detective Chad said.
Sara hopped out of her car and walked up the long path that led to the house. Right away she was ushered inside by Mrs. Glen. "Detective, I'm so glad you came. The last place I saw Mr. Gooding was in his room. I suspected that would be your first question." Mrs. Glen said somewhat nervously. She walked Sara into the other room. "Up here," Mrs. Glen called from a twisting flight of stairs. The front door banged shut just as Sara started up the steps. "Oh, I must have left the door open. The wind must have shut it." Mrs. Glen said. Again they started up the stairs.
They walked up the enormous stairway. Halfway up detective Sara noticed a weather vane through the window. She realized that the wind was blowing west and in order for it to have shut the door it would have to have been blowing east. Then Sara realized for the first time that there was a third set of footsteps on the stairs. Then it dawned on her and she realized she had walked into a trap. How did Sara know she had walked into a trap?
Sara hopped out of her car and walked up the long path that led to the house. Right away she was ushered inside by Mrs. Glen. "Detective, I'm so glad you came. The last place I saw Mr. Gooding was in his room. I suspected that would be your first question." Mrs. Glen said somewhat nervously. She walked Sara into the other room. "Up here," Mrs. Glen called from a twisting flight of stairs. The front door banged shut just as Sara started up the steps. "Oh, I must have left the door open. The wind must have shut it." Mrs. Glen said. Again they started up the stairs.
They walked up the enormous stairway. Halfway up detective Sara noticed a weather vane through the window. She realized that the wind was blowing west and in order for it to have shut the door it would have to have been blowing east. Then Sara realized for the first time that there was a third set of footsteps on the stairs. Then it dawned on her and she realized she had walked into a trap. How did Sara know she had walked into a trap?
Hint:
Detective Sara Dunts realized she had walked into a trap when she heard the extra set of footsteps. Hearing the footsteps on the stairs made her remember what her partner had said, "Mr. John Gooding had mysteriously vanished from his one story home." She then realized that this was not Mr. Goodings home because at that very moment she realized that she was climbing stairs in a supposedly one story house. Sara immediately called for backup and arrested Mrs. Glen. She then walked down the stairs to find Mr. Gooding near the bottom. The two had planned on kidnapping and killing Sara for putting Mr. Goodings niece and Mrs. Glens son in jail for murder. Both went to jail to serve their time. Did you answer this riddle correctly?
YES NO
YES NO
Everyone Wants More Riddle
Everyone wants more of it to feel special, and to have more of it opens the door to more opportunity. What is it?
Hint:
Boxes Of Balls Riddle
The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.
Boxes are labeled but all labels are wrong!
You are allowed to open one box, pick one ball at random, see its color and put it back into the box, without seeing the color of the other ball.
How many such operations are necessary to correctly label the boxes?
Boxes are labeled but all labels are wrong!
You are allowed to open one box, pick one ball at random, see its color and put it back into the box, without seeing the color of the other ball.
How many such operations are necessary to correctly label the boxes?
Hint:
Just One!
Because we know all labels are wrong.
So the BW box must be either BB or WW. Selecting one ball from BW will let you know which.
And the other two boxes can then be worked out logically. Did you answer this riddle correctly?
YES NO
Because we know all labels are wrong.
So the BW box must be either BB or WW. Selecting one ball from BW will let you know which.
And the other two boxes can then be worked out logically. Did you answer this riddle correctly?
YES NO
Joseph And Lena Riddle
Joseph and Lena are found dead on the floor with some water around. The windows are open and a strong wind draft is blowing the curtains around. How did they die?
Hint:
Joseph and Lena were goldfishes. The wind tipped their bowl over, hence killing them! Did you answer this riddle correctly?
YES NO
YES NO
Secret Code Riddle
A thief enters a shop and threatens the clerk, forcing him to open the safe. The clerk says, "The code for the safe is different every day, and if you hurt me you'll never get the code". But the thief manages to guess the code on his own.
How did he do it?
How did he do it?
Hint:
Hidden Gems Riddle
Find the names of 10 gems or precious stones hidden in the following story. Each one spans at least two words.
Sir Gade rode toward a castle atop a zebra at a steady gallop, a long way from home. He arrived at the gate and the keeper knelt in shame. Thy steed must be tired. Sir Gade replied, I am on direct orders from the King. Let me through. A cougar, nettled by the noise, emerged from a shrub. You must save me! cried the gate man. Sir Gade, eyes filled with rancor, alighted and gazed toward the sky. An item fell from his cloak as drove his sword into the cougars spine. Let me pass! cried Sir Gade. The gate keeper, stunned from his saga, tentatively opened the gate, then retrieved the fallen item.
Sir Gade rode toward a castle atop a zebra at a steady gallop, a long way from home. He arrived at the gate and the keeper knelt in shame. Thy steed must be tired. Sir Gade replied, I am on direct orders from the King. Let me through. A cougar, nettled by the noise, emerged from a shrub. You must save me! cried the gate man. Sir Gade, eyes filled with rancor, alighted and gazed toward the sky. An item fell from his cloak as drove his sword into the cougars spine. Let me pass! cried Sir Gade. The gate keeper, stunned from his saga, tentatively opened the gate, then retrieved the fallen item.
Hint:
1. topaz atop a zebra
2. opal gallop, a long
3. amethyst shame. Thy steed
4. diamond replied, I am on direct
5. garnet cougar, nettled
6. ruby shrub. You
7. coral rancor, alighted
8. kyanite sky. An item
9. spinel spine. Let
10. agate saga, tentatively Did you answer this riddle correctly?
YES NO
2. opal gallop, a long
3. amethyst shame. Thy steed
4. diamond replied, I am on direct
5. garnet cougar, nettled
6. ruby shrub. You
7. coral rancor, alighted
8. kyanite sky. An item
9. spinel spine. Let
10. agate saga, tentatively Did you answer this riddle correctly?
YES NO
The Big Metal Box Riddle
In a cave there is a treasure within a big metal box with a lock on it. There is also a monster in the cave that has two keys with him; one gold and the other silver. The monster will give you only one chance to open the lock using one of the keys. If the box doesnt open, the monster will kill you. Since the monster is a bit helpful it would give you a clue in finding out the correct key. Can you choose the correct key by deciphering the below clue?
A GKOY OEPD LYEO DCNO EAAR NNN
A GKOY OEPD LYEO DCNO EAAR NNN
Hint:
The gold key will open the lock.
The clue says A Golden Key Can Open Any Door. Decipher the message by taking the first letter of each word, then the second letter of each word, then the third letter and so on to construct the sentence. Did you answer this riddle correctly?
YES NO
The clue says A Golden Key Can Open Any Door. Decipher the message by taking the first letter of each word, then the second letter of each word, then the third letter and so on to construct the sentence. Did you answer this riddle correctly?
YES NO
3 Envelops Riddle
You are sitting in front of your interviewer. He gives you three envelopes. One of them contains an offer letter and the other two are empty. You pick up one of them. Now, the interviewer opens up one of the envelope lying on the table and you find out that it is blank.
Now, he gives you a chance to switch your envelope with the one on the table. Would you switch it? Why or why not?
Now, he gives you a chance to switch your envelope with the one on the table. Would you switch it? Why or why not?
Hint:
Yes, you should switch the envelope. In the beginning when you picked up the envelope, you had a 1/3 probability of finding an offer letter in the envelope. There was 2/3 chance that the letter was there in the two envelopes on the table.
If you keep your selected envelope, you still have a 1/3 chance of finding an offer letter in that. However, since the interviewer has removed one empty envelope from the table, if you switch, you have a probability of 2/3 that the offer letter is inside that. Did you answer this riddle correctly?
YES NO
If you keep your selected envelope, you still have a 1/3 chance of finding an offer letter in that. However, since the interviewer has removed one empty envelope from the table, if you switch, you have a probability of 2/3 that the offer letter is inside that. Did you answer this riddle correctly?
YES NO
Attacked By A Burglar Riddle
My wife was attacked by a burglar when I was on my way home from work. She stabbed him with a butcher knife and killed him. The police say it was an obvious case of self-defense. When I went to pick her up from the police station, she said. - "When I heard the doorbell I thought it was you, but then a masked man jumped me as soon as I opened the door!" - "You must have been so scared" - I said - "But you're safe now" - I hugged her tightly.
How did she kill the burglar so fast when he attacked her at the door?
How did she kill the burglar so fast when he attacked her at the door?
Hint:
His wife came to the door with a butcher knife because she thought her husband was coming home. She was planning to kill the husband. Did you answer this riddle correctly?
YES NO
YES NO
A Boy At The Carnival
A young boy was at the carnival. He was walking past a kiosk where an old man was sitting.
"Do you want to play a game?" the old man said to him.The young boy was intrigued. "What kind of game?" he asked.
"It's a very simple game." said the old man. "I will tell you the rules. I have ten large metal boxes. Inside one of the boxes is the prize money. One thousand dollars."
"A thousand bucks, huh?" asked the boy. "What's the catch?"
"The boxes are sturdy and strong," said the old man. "Much too strong to be opened with your bare hands. They are also airtight and cannot be damaged by a hammer, an axe or even a chainsaw."
"So they're impossible to open?" said the boy.
"Not impossible." said the man. "I have a blowtorch which can be used to open the boxes."
"Is there a time limit?" asked the boy.
"You can take as much time as you want." said the old man. "When you find the prize money, it's all yours. So, do you want to play the game?"
"Well, I don't how I could possibly lose," said the boy. "OK. I'll play your game."
The old man smiled. "I'll make it very easy for you", he said. "There are ten metal boxes, but if you give me five dollars, I will start you right next to the prize money."
The boy happily took out his wallet and handed a crisp five dollar note to the old man. There was a mischievous grin on the old man's face.The game started.The prize money was right in front of the boy. He could see it. He could touch it.Even though he won the game, the boy was never able to spend the money. He died shortly after he won the game.
How did the boy die?
"Do you want to play a game?" the old man said to him.The young boy was intrigued. "What kind of game?" he asked.
"It's a very simple game." said the old man. "I will tell you the rules. I have ten large metal boxes. Inside one of the boxes is the prize money. One thousand dollars."
"A thousand bucks, huh?" asked the boy. "What's the catch?"
"The boxes are sturdy and strong," said the old man. "Much too strong to be opened with your bare hands. They are also airtight and cannot be damaged by a hammer, an axe or even a chainsaw."
"So they're impossible to open?" said the boy.
"Not impossible." said the man. "I have a blowtorch which can be used to open the boxes."
"Is there a time limit?" asked the boy.
"You can take as much time as you want." said the old man. "When you find the prize money, it's all yours. So, do you want to play the game?"
"Well, I don't how I could possibly lose," said the boy. "OK. I'll play your game."
The old man smiled. "I'll make it very easy for you", he said. "There are ten metal boxes, but if you give me five dollars, I will start you right next to the prize money."
The boy happily took out his wallet and handed a crisp five dollar note to the old man. There was a mischievous grin on the old man's face.The game started.The prize money was right in front of the boy. He could see it. He could touch it.Even though he won the game, the boy was never able to spend the money. He died shortly after he won the game.
How did the boy die?
Hint:
The man put the inside of the box since he said for five dollars, he'd put the boy next to the money. Since the box was airtight, he suffocated Did you answer this riddle correctly?
YES NO
YES NO
A Windless Day Riddle
Your friend tells you about a story he once tried to impress a young lady with, but instead got a slap in the face. He wants you to attempt to see the flaw: It was a hot and windless day, in our bunker, when suddenly one of ours yelled: "Enemy!" We opened fire on them, leaving one hundred of them dead before they retreated. I was checking a dead captain's glasses when the shout came that they were incoming again, and the CO ordered us to open up on them with our mortars, when I yelled: "Cease fire! They're Americans!" Later, an American colonel thanked me for my work after I said that I saw their flag, waving back and forth in the wind. What is wrong with this story?
Hint:
At the beginning, it was said that "It was a hot and windless day," yet at the end, it is said that "The flag was waving back and forth". Had it been windless, the flag would have been limp. Did you answer this riddle correctly?
YES NO
YES NO
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