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
Billy's Bicycle Riddle
Bill rode his bicycle 300 miles. Three tires were used equally in accumulating this distance. How many miles of wear did each tire sustain?
Hint:
200 miles. For every mile traveled, each of the two tires sustained one mile of usage. Therefore, in a total of 300 miles traveled, there would be a total of 600 miles of wear. And 600 divided by three is 200. Did you answer this riddle correctly?
YES NO
YES NO
Five Potatoes Riddle
Hint:
Show White's Dwarfs Riddle
Hint:
I Have A Source Riddle
I have a source but Im not a journalist
I have a delta but Im not a Greek alphabet
I have banks on both sides of me but Im not surrounded by money
I flow but Im not a bloodstream
Im full of water but Im not a fish tank
What am I?
I have a delta but Im not a Greek alphabet
I have banks on both sides of me but Im not surrounded by money
I flow but Im not a bloodstream
Im full of water but Im not a fish tank
What am I?
Hint:
A Pack Of 40 Cards
A pack of cards has 40 cards. You are blindfolded. Out of 40, 25 cards are facing down while 15 are facing up. You have been asked to divide this pack of cards into two decks - so that each deck contains an equal number of face up cards. Remember, you are blindfolded.
How will you do it?
How will you do it?
Hint:
Create a new deck of the exactly same number of cards as are face up cards in the original deck.Take 15 number of cards in a new deck and change their face direction. For example- You create a new deck of 15 cards and out of 15, 5 faces up in a new deck. So remaining 10 faces up are in the old deck. But hey! while creating the new deck you reversed the face direction of new cards. So actually the 5 cards which were facing up are actually face down in the new deck while 10 faces up. Did you answer this riddle correctly?
YES NO
YES NO
21 Jars Riddle
You have 21 jars with you. Out of them, 7 are filled with water, 7 are half-full with water and 7 are empty. How will you distribute the jars among three people such that each one of them gets the equal number of jars and equal amount of water?
Hint:
Give 3 full, 1 half-full and 3 empty bottles to the first person.
Give 3 full, 1 half-full and 3 empty bottles to the second person.
Give 1 full, 5 half-full and 1 empty bottle to the third person. Did you answer this riddle correctly?
YES NO
Give 3 full, 1 half-full and 3 empty bottles to the second person.
Give 1 full, 5 half-full and 1 empty bottle to the third person. Did you answer this riddle correctly?
YES NO
The 2 Barbershops
There is a small town on the East Coast that has 2 barbershops each with a single barber, and on opposite sides of town. The barbershop in the good part of town is immaculate. The floors and windows are washed and the air is fresh. The barber is very friendly, always smiling, he has shined shoes, a nice head of hair, and a clean dress shirt. The barbershop in the bad part of town is a mess. The entire barbershop is covered with a layer of dirt, and the air smells of trash. The barber always has a frown on his face. His skin is oily, his hair is ragged, and there are always stains visible on his shirt.
A man comes into town and hears of both barbershops and the man decides to go to the dirty barbershop in the bad part of town. Why does he do this?
A man comes into town and hears of both barbershops and the man decides to go to the dirty barbershop in the bad part of town. Why does he do this?
Hint:
The clean-cut barber must have his hair cut by the dirty barber and the dirty barber by the clean-cut barber. So its obvious that the dirty barber gives a better haircut. Did you answer this riddle correctly?
YES NO
YES NO
Little Johnny's Bet Riddle
Little Johnny is walking home. He has $300 he has to bring home to his mom. While he is walking a man stops him and gives him a chance to double his money. The man says "I'll give you $600 if you can roll 1 die and get a 4 or above, you can roll 2 dice and get a 5 or 6 on at least one of them, or you can roll 3 dice and get a 6 on at least on die. If you don't I get your $300."
What does Johnny do to have the best chance of getting home with the money?
What does Johnny do to have the best chance of getting home with the money?
Hint:
He just doesn't take the bet. This gives him a 100 percent chance of getting the money home. If he takes the bet with 1 die he has a 50 percent chance of winning. If he takes the bet with 2 dice he has about a 56 percent chance of winning. If he takes the bet with 3 dice he has about a 42 percent chance of winning. Did you answer this riddle correctly?
YES NO
YES NO
The Plane Crash
There was an airplane crash, every single person on board died, but yet two people survived. How is this possible?
Hint:
52 Pickup Riddle
How will you do it?
Hint:
Take 10 number of cards in a new deck and change their face direction. For example- You create a new deck of 10 cards and out of 10, 3 faces up in the new deck. So remaining 7 faces up are in the old deck. But hey! while creating the new deck you reversed the face direction of new cards. So actually the 3 cards which were facing up are actually face down in the new deck while 7 faces up. Did you answer this riddle correctly?
YES NO
YES NO
Hierarchy Is No More Riddle
A king of riches. A pawn of poor. After the game the same box they board. It takes them where hierarchy is no more. What is it?
Hint:
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 Jug Full Of Beer
A barman is having a 12 liters jug full of beer. He needs to divide or split that beer into two equal parts. All he has is two empty jugs of capacity 8 liters and 5 liters.
How will he do it using them?
How will he do it using them?
Hint:
First fill the 8 liters jug complete - 4, 8, 0
Fill the 5 liters jug with 8 liters jug - 4, 3, 5
Pour back the beer from 5 liters jug to 12 liters jug - 9, 3, 0
Pour the 3 liters from 8 liters jug to 5 liters jug - 9, 0, 3
Fill the 8 liters jug completely from 12 liters jug - 1, 8, 3
Fill the 5 liters jug from the 8 liters jug - 1, 6, 5
Pour the entire 5 liters jug back in 12 liters jug - 6, 6, 0
You have successfully split the beer into two equal parts. Did you answer this riddle correctly?
YES NO
Fill the 5 liters jug with 8 liters jug - 4, 3, 5
Pour back the beer from 5 liters jug to 12 liters jug - 9, 3, 0
Pour the 3 liters from 8 liters jug to 5 liters jug - 9, 0, 3
Fill the 8 liters jug completely from 12 liters jug - 1, 8, 3
Fill the 5 liters jug from the 8 liters jug - 1, 6, 5
Pour the entire 5 liters jug back in 12 liters jug - 6, 6, 0
You have successfully split the beer into two equal parts. Did you answer this riddle correctly?
YES NO
The River Crossing
A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.
How will they cross the river?
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.
How will they cross the river?
Hint:
The guard and the prisoner cross the river
The guard comes back
The guard and the girl cross the river.
The guard and the prisoner comes back.
The mother and the girl cross the river.
Mother comes back
The mother and the father cross the river
Father comes back
The guard and the prisoner cross the river
Mother comes back
The father and the mother cross the river
Father comes back
The father and the boy cross the river
The guard and the prisoner comes back
The guard and the boy cross the river
The guard comes back
The guard and the prisoner cross the river. Did you answer this riddle correctly?
YES NO
The guard comes back
The guard and the girl cross the river.
The guard and the prisoner comes back.
The mother and the girl cross the river.
Mother comes back
The mother and the father cross the river
Father comes back
The guard and the prisoner cross the river
Mother comes back
The father and the mother cross the river
Father comes back
The father and the boy cross the river
The guard and the prisoner comes back
The guard and the boy cross the river
The guard comes back
The guard and the prisoner cross the river. Did you answer this riddle correctly?
YES NO
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