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
The Long Island Iced Tea
Two guys walk into a bar. They both order the special, Long Island Iced Tea, which is poured from the same pitcher. One of them drinks his drink slowly and one of them drinks it fast. They walk outside and suddenly the guy who drank his Long Island Tea slowly drops to the ground and dies. They order an autospy and find that he died from poison. How could this be if the other guy drank the same tea and didnt even get sick?
Hint:
TTwo guys walk into a bar. They both order the special, Long Island Iced Tea, which is poured from the same pitcher. One of them drinks his drink slowly and one of them drinks it fast. They walk outside and suddenly the guy who drank his Long Island Tea slowly drops to the ground and dies. They order an autospy and find that he died from poison. How could this be if the other guy drank the same tea and didnt even get sick? Did you answer this riddle correctly?
YES NO
YES NO
Almost Hit By A Car Riddle
A man walked home after having been out drinking. He walked down the middle of a deserted country road. There were no streetlights to illuminate the road and there was no moonlight. He was dressed all in black. Suddenly a car that did not have its headlights on came racing down the road. At the last moment, the driver of the car saw the man and swerved to avoid him.
How did he manage to see him?
How did he manage to see him?
Hint:
He was returning home in the middle of the day, so anyone could have seen him. Did you answer this riddle correctly?
YES NO
YES NO
A Complicated Coop Riddle
There was a farmer and he had a problem with his coop (the place where you keep the birds), and he wanted to go check it out. When he got there he noticed that there was a rooster on the barn. Now the barn was shaped with a triangle type top. But suddenly the rooster laid an egg. Which side did it roll on?
Hint:
A Man In The Shadows Riddle
You are walking down a dark alley at night. Suddenly, a man jumps out of the shadows with a gun. He tells you "I am here to kill you. Tell me one wish. I will not fulfill it, but I will kill you. If you say the right thing, you will be saved." What do you say?
Hint:
Soldiers On The River
A detachment of soldiers must cross a river. The bridge is broken, the river is deep. What to do? Suddenly the officer-in-charge spots two boys playing in a rowboat by the shore. The boat is so tiny, however, that it can only hold 2 boys or 1 soldier. Still - all the soldiers succeed in crossing the river in the boat. How?
Hint:
First the boys cross the river. One stays ashore while the other brings the boat to the soldiers. A soldier takes the boat back across and the boy that stayed before brings the boat back and picks up the other boy. The boat takes the two boys back and one remains while the other boy returns the boat to the soldiers. This is repeated until all of the soldiers are on the opposite side of the river. Did you answer this riddle correctly?
YES NO
YES NO
Letters In A Lightning Storm
A man was sitting in his cabin writing a letter during a lightning storm, when suddenly he died. How did he die?
Hint:
The Woman On The Train
My job means I'm always on a train. I was on the train again today when, suddenly a woman appeared in front of me. I can remember her face clearly. It's really depressing.
Who was this mysterious woman?
Who was this mysterious woman?
Hint:
The person is a train driver and the woman jumped in front of his train. Did you answer this riddle correctly?
YES NO
YES NO
A Walk In The Desert Riddle
Four men walk into the desert. Suddenly all four are simultaneously knocked out. They awake buried to their heads in the sand unable to look anywhere but straight ahead. They are positioned so that each man sees another's head before him. However between the first and second man there is a separating wall.
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
Hint:
The third man. This is because he knows there are only two of each color cap. If the man behind him (the fourth man) saw two caps that were the same color in front of him, he would know that his own must be the opposite. However, because the caps alternate in color. The fourth man has only a 50% chance of getting his hat color correct, so therefore he stays quiet. The third man realizes that the fourth man is quiet because he must not see two caps of the same color in front of him, otherwise the fourth man would say the opposite of the caps in front of him. Therefore, the third man presumes his own cap must be the opposite of the mans in front of him, and his presumption is correct. Under this same logic, after the third man speaks his color hat, the second man, even though he sees only wall, would be the next to go free, because he knows his cap must be the opposite of whichever color the third mans cap was. 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
The Egg Spinning Competition
You are a junior detective investigating a case. Boys at an apartment complain that every day, they have an egg spinning competition with only raw eggs, and every day one particular boy wins.
The boys want you to find out how. You are observing the boy spinning an egg when suddenly it drops to the floor. The apartment clerk casually hands him a broom to clean it up, as if it happens every day. You now know why the boy always wins the daily competition. How?
The boys want you to find out how. You are observing the boy spinning an egg when suddenly it drops to the floor. The apartment clerk casually hands him a broom to clean it up, as if it happens every day. You now know why the boy always wins the daily competition. How?
Hint:
The clerk handed the boy a broom, so the egg the boy was spinning must have been hard-boiled. If the egg was raw, the clerk would have handed the boy a mop. Did you answer this riddle correctly?
YES NO
YES NO
One Snowy Night Riddle
One snowy night, Sherlock Holmes was in his house sitting by a fire. All of a sudden a snowball came crashing through his window, breaking it. Holmes got up and looked out the window just in time to see three neighborhood kids who were brothers run around a corner.
Their names were John Crimson, Mark Crimson and Paul Crimson. The next day Holmes got a note on his door that read ? Crimson. He broke your window. Which of the three Crimson brothers should Sherlock Holmes question about the incident?
Their names were John Crimson, Mark Crimson and Paul Crimson. The next day Holmes got a note on his door that read ? Crimson. He broke your window. Which of the three Crimson brothers should Sherlock Holmes question about the incident?
Hint:
He should question Mark Crimson.
? = question MARK, so the note on the door reads Question Mark Crimson. He broke your window. Did you answer this riddle correctly?
YES NO
? = question MARK, so the note on the door reads Question Mark Crimson. He broke your window. Did you answer this riddle correctly?
YES NO
Going To Heaven Riddle
Stephen died of heart attack. His soul was received in heaven. He was astonished to find himself as young as he had been in his young adult age. He looked around and there were thousands of young and naked people. His eyes searched to find someone familiar and suddenly he noticed Adam and Eve.
How did Stephen recognize them?
How did Stephen recognize them?
Hint:
Adam and Eve were the only people without navel. As they were not born out of a mother, they never had umbilical cords and thus never had navels. Did you answer this riddle correctly?
YES NO
YES NO
The Card Trick Riddle
A couple had to take shelter in a hotel for they could not proceed their journey in the rain. Having nothing to do at all, they started playing cards. Suddenly there was a short circuit and the lights went off. The husband inverted the position of 15 cards in the deck (52 cards normal deck) and shuffled the deck.
Now he asked his wife to divide the deck into two different piles which may not be equal but both of them should have equal number of cards facing up. There was no source of light in the room and the wife was unable to see the cards.
For a certain amount of time, she thought and then divided the cards in two piles. To the husbands astonishment, both of the piles had equal number of cards facing up.
How did she do it?
Now he asked his wife to divide the deck into two different piles which may not be equal but both of them should have equal number of cards facing up. There was no source of light in the room and the wife was unable to see the cards.
For a certain amount of time, she thought and then divided the cards in two piles. To the husbands astonishment, both of the piles had equal number of cards facing up.
How did she do it?
Hint:
The answer is very simple. All she had to do is take the fifteen cards from the top and reverse them. This would make another pile out of that and there will be two piles - one of 15 cards and one of 37 cards. Also both of them will have the same number of inverted cards.
Just think about it and if the mathematical explanation will help you understand better, here it is.
Assume that there were p inverted cards initially in the top 15 cards. Then the remaining 37 cards will hold 15-p inverted cards.
Now when she reverses the 15 cards on the top, the number of inverted cards will become 15-p and thus the number of inverted cards in both of the piles will become same. Did you answer this riddle correctly?
YES NO
Just think about it and if the mathematical explanation will help you understand better, here it is.
Assume that there were p inverted cards initially in the top 15 cards. Then the remaining 37 cards will hold 15-p inverted cards.
Now when she reverses the 15 cards on the top, the number of inverted cards will become 15-p and thus the number of inverted cards in both of the piles will become same. Did you answer this riddle correctly?
YES NO
The Elevator Button Riddle
A man enters a building. He presses the elevator button and he suddenly realizes that his wife is dead. How?
Hint:
By pressing the elevator button, he realizes that the electricity has gone off. His wife was connected to an electrical device for health issues, so he realizes that his wife is dead. Did you answer this riddle correctly?
YES NO
YES NO
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