Train Smoke Riddle
An electric train is going south at 98 mph. the wind is blowing northeast. Which direction is the smoke blowing?
Hint:
Two Trains Riddle
Two incredibly high speed trains are charging at a speed of 250 mph, on the same track, starting from opposite directions. They leave at the same exact time and continue at the same exact speed. They never slow down. The two trains never touch...how is that possible?
Hint:
The two trains begin back-to-back and charge the track away from each other. Did you answer this riddle correctly?
YES NO
YES NO
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
Discharge Of The Rifle
Anderson, Biggs, and Carpenter were staying together at a place by the seaside. One day they went out in a boat and were a mile at sea when a rifle was fired on shore in their direction.
It seems that Anderson only heard the report of the gun, Biggs only saw the smoke, and Carpenter merely saw the bullet strike the water near them. Which of them first knew of the discharge of the rifle?
It seems that Anderson only heard the report of the gun, Biggs only saw the smoke, and Carpenter merely saw the bullet strike the water near them. Which of them first knew of the discharge of the rifle?
Hint:
Biggs, who saw the smoke, would be first; Carpenter, who saw the bullet strike the water, would be second; and Anderson, who heard the report, would be last of all. Did you answer this riddle correctly?
YES NO
YES NO
Throwing Rum Riddle
What is the easiest way to throw a bottle of Rum, have it stop, and completely reverse direction after traveling a short distance?
Hint:
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
Flip The Switch Riddle
There is a prison with 100 prisoners, each in separate cells with no form of contact. There is an area in the prison with a single light bulb in it. Each day, the warden picks one of the prisoners at random, even if they have been picked before, and takes them out to the lobby. The prisoner will have the choice to flip the switch if they want. The light bulb starts off.
When a prisoner is taken into the area with the light bulb, he can also say "Every prisoner has been brought to the light bulb." If this is true all prisoners will go free. However, if a prisoner chooses to say this and it's wrong, all the prisoners will be executed. So a prisoner should only say this if he knows it is true for sure.
Before the first day of this process begins, all the prisoners are allowed to get together to discuss a strategy to eventually save themselves.
What strategy could they use to ensure they will go free?
When a prisoner is taken into the area with the light bulb, he can also say "Every prisoner has been brought to the light bulb." If this is true all prisoners will go free. However, if a prisoner chooses to say this and it's wrong, all the prisoners will be executed. So a prisoner should only say this if he knows it is true for sure.
Before the first day of this process begins, all the prisoners are allowed to get together to discuss a strategy to eventually save themselves.
What strategy could they use to ensure they will go free?
Hint:
Only allow one prisoner to turn the light bulb off and all of the others turn it on if they have never turned it on before. If they have turned it on before they do nothing. The prisoner that can turn it off then knows they have all been there and saves them all when he has turned it off 99 times. Did you answer this riddle correctly?
YES NO
YES NO
The Most Precious Commodity Riddle
What is the most precious commodity?
That which when needed seemingly is never enough,
Yet otherwise can be boringly plentiful.
While waking is oft dreamt of,
Whilst pining can scarcely be thought of.
For beings, is allotted in finite but indefinite quantity.
The more thats given, the more is wasted.
Freedom is akin though this is something more simple,
Not related to virtue or sin.
Unless perhaps, without freedom, or its limit.
What is it?
That which when needed seemingly is never enough,
Yet otherwise can be boringly plentiful.
While waking is oft dreamt of,
Whilst pining can scarcely be thought of.
For beings, is allotted in finite but indefinite quantity.
The more thats given, the more is wasted.
Freedom is akin though this is something more simple,
Not related to virtue or sin.
Unless perhaps, without freedom, or its limit.
What is it?
Hint:
Snow White's Photography Riddle
Hint:
The Tiger, Princess And Merchant Riddle
A merchant boy asks the king for the princess's hand in marriage. The king replies, "Tomorrow I will set a bowl with two pieces of paper in it in front of the entire kingdom. One piece will say Tiger and one will say Princess. If you choose tiger, you will be fed to the tigers. If you choose princess, you will marry the princess." The boy later finds out that the king is planning to trick him by putting the word tiger on both pieces of paper. The next day the boy picks a paper and ends up marrying the princess. How does he do it?
Hint:
The boy chooses the paper and eats it without showing anyone the word on the paper and says, "I have made my decision. If the paper with tiger on it is left then I must have chosen the princess." They opened the remaining piece with the word tiger written on it. The boy got to marry his princess after all. 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
High Performance MAC Riddle
A high performance MAC and and a high performance IBM are in a store display window. A customer walks into the store. Which one does he choose?
Hint:
The high performance IBM. There is no such thing as a high performance MAC. Did you answer this riddle correctly?
YES NO
YES NO
Grapeland To Applecity
You have to send 3,000 grapes 1,000 kilometers from grapecity to appleland. Your truck can carry 1,000 grapes at a time. Every time you travel a kilometer towards appleland you must pay a tax of 1 grape but you pay nothing when going in the other direction (towards grapecity).
What is highest number of grapes you can get to appleland?
What is highest number of grapes you can get to appleland?
Hint:
Step one: First you want to make 3 trips of 1,000 grapes 333 kilometers. You will be left with 2,001 grapes and 667 kilometers to go.
Step two: Next you want to take 2 trips of 1,000 grapes 500 kilometers. You will be left with 1,000 grapes and 167 kilometers to go (you have to leave a grape behind).
Step three: Finally, you travel the last 167 kilometers with one load of 1,000 grapes and are left with 833 grapes in appleland. Did you answer this riddle correctly?
YES NO
Step two: Next you want to take 2 trips of 1,000 grapes 500 kilometers. You will be left with 1,000 grapes and 167 kilometers to go (you have to leave a grape behind).
Step three: Finally, you travel the last 167 kilometers with one load of 1,000 grapes and are left with 833 grapes in appleland. Did you answer this riddle correctly?
YES NO
A Rickety Bridge Riddle
Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?
Hint:
17 mins.
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
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
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