Bank Teller Biking Riddle
Hint:
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
3 Princesses Riddle
Three princes were in love with a princess. the king said the prince who could win a made-up game would marry the princess. The rules were simple: the princes were to stand on boxes in different corners of a room while the princess was in the middle. They were not allowed to use ANYTHING and were not allowed to walk on the carpet. The game was won by touching the princess' hand. One of princes found out how to touch the princess' hand and married her. How did he do it?
Hint:
He called the princess and told her to walk to him and to touch his hand. Did you answer this riddle correctly?
YES NO
YES NO
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
10 Boxes Riddle
There are ten boxes containing some balls. Each of the ball weighs exactly 10 grams. One of those boxes have defective balls (all the defective balls weigh 9 grams each).
An electronic weighing machine is provided to you and you are allowed only one chance of weighing on it.
How will you find out which box has defective balls ?
An electronic weighing machine is provided to you and you are allowed only one chance of weighing on it.
How will you find out which box has defective balls ?
Hint:
Let us simplify boxes by naming them from 1 to 10.
Now the trick here is to pick different number of balls from different boxes. So to simplify things, we will pick balls corresponding to box number.
Thus, pick 1 ball from Box 1, 2 balls from box 2, 3 balls from box 3 and so on. You will have 55 balls altogether. Now, put them all in the balance.
If all balls were weighing accurate 10 grams, the total weight of the 55 balls would have been 550 grams. But one of the box must have had the defective balls.
Suppose if the defective balls were in box number 2, then the total weight will be 2 grams less than 550. If the defective balls were in box 8, the total weight will be less than 8 grams from 550. In this way, you will be able to identify which box has the defective balls. Did you answer this riddle correctly?
YES NO
Now the trick here is to pick different number of balls from different boxes. So to simplify things, we will pick balls corresponding to box number.
Thus, pick 1 ball from Box 1, 2 balls from box 2, 3 balls from box 3 and so on. You will have 55 balls altogether. Now, put them all in the balance.
If all balls were weighing accurate 10 grams, the total weight of the 55 balls would have been 550 grams. But one of the box must have had the defective balls.
Suppose if the defective balls were in box number 2, then the total weight will be 2 grams less than 550. If the defective balls were in box 8, the total weight will be less than 8 grams from 550. In this way, you will be able to identify which box has the defective balls. Did you answer this riddle correctly?
YES NO
Three Switches Riddle
Three switches outside a windowless room are connected to three light bulbs inside the room. How can you determine which switch is connected to which bulb if you are only allowed to enter the room once?
Hint:
Switch on the first switch, leave it for a minute, and then switch it off again. Then switch on the second switch and enter the room. The second switch will be connected to the light that is on, the first switch will be connected to the light with the warm bulb, and the third switch will be connected to the light with the cold bulb. Did you answer this riddle correctly?
YES NO
YES NO
Switch Or Stick Riddle
There are three doors: Door 1, Door 2, and Door 3. Behind one of these doors lies eternal bliss, but behind the others lies eternal despair. You are allowed to choose any door, and you pick Door 1. Suddenly, Door 3 is swung open and revealed to be despair! You are give another choice: you may stick with the door you chose (1) or switch to the other (2). What should you do?
Hint:
The answer may surprise you: switch. Due to something called the Monty Hall Paradox, you will statistically have a better chance of making the "correct" choice. The concept is as follows:
Door 1 Door 2 Door 3
All have an equal chance to be correct:
Door 1: 1/3 Door 2: 1/3 Door 3: 1/3
After choosing Door 1, the remaining two have a 2/3 chance of containing the right choice:
Door1: 1/3 Doors 2 3: 2/3
If Door 3 is removed, the probability does not shift to 50:50. Instead, it is:
Door 1: 1/3 Door 2: 2/3
Thus, you should switch. Did you answer this riddle correctly?
YES NO
Door 1 Door 2 Door 3
All have an equal chance to be correct:
Door 1: 1/3 Door 2: 1/3 Door 3: 1/3
After choosing Door 1, the remaining two have a 2/3 chance of containing the right choice:
Door1: 1/3 Doors 2 3: 2/3
If Door 3 is removed, the probability does not shift to 50:50. Instead, it is:
Door 1: 1/3 Door 2: 2/3
Thus, you should switch. Did you answer this riddle correctly?
YES NO
Moving Quarters Riddle
Hint:
Hold down one of the quarters very firmly. Take another coin and hit it against the quarter you are holding down. Tap hard enough to move the quarter next to it aside. Did you answer this riddle correctly?
YES NO
YES NO
1 Cookie Riddle
A boy is allowed to take one cookie from the jar, but at the end there are no cookies left, but he kept his promise of one cookie. How were all the cookies gone?
Hint:
Jumping Duck Riddle
A duck arrives near a lake. He sees a sign were it is written "No swimming allowed.", but the duck jumps into the water. Why?
Hint:
The Parrot Doors Riddle
There are two doors. One door lead to Heaven, while the other leads to Hell. A parrot stands in front of each door. One parrot always tells a lie, while the other always tells the truth. You do not know which parrot or door is which. You are allowed to only ask one question. So, what one question must you ask to determine which door is which, so you can finally go to Heaven? (Hint: The question involves what one parrot would say about the doors.)
Hint:
It doesn't matter which parrot you ask the question to, but the question would be, "What door would the other parrot say is Heaven?". Then you would choose the other door. Did you answer this riddle correctly?
YES NO
YES NO
100 Blank Cards Riddle
Someone offers you the following deal:
There is a deck of 100 initially blank cards. The dealer is allowed to write ANY positive integer, one per card, leaving none blank. You are then asked to turn over as many cards as you wish. If the last card you turn over is the highest in the deck, you win; otherwise, you lose.
Winning grants you $50, and losing costs you only the $10 you paid to play.
Would you accept this challenge?
There is a deck of 100 initially blank cards. The dealer is allowed to write ANY positive integer, one per card, leaving none blank. You are then asked to turn over as many cards as you wish. If the last card you turn over is the highest in the deck, you win; otherwise, you lose.
Winning grants you $50, and losing costs you only the $10 you paid to play.
Would you accept this challenge?
Hint: Perhaps thinking in terms of one deck is the wrong approach.
Yes!
A sample strategy:
Divide the deck in half and turn over all lower 50 cards, setting aside the highest number you find. Then turn over the other 50 cards, one by one, until you reach a number that is higher than the card you set aside: this is your chosen "high card."
Now, there is a 50% chance that the highest card is contained in the top 50 cards (it is or it isn't), and a 50% chance that the second-highest card is contained in the lower 50. Combining the probabilities, you have a 25% chance of constructing the above situation (in which you win every time).
This means that you'll lose three out of four games, but for every four games played, you pay $40 while you win one game and $50. Your net profit every four games is $10.
Obviously, you have to have at least $40 to start in order to apply this strategy effectively. Did you answer this riddle correctly?
YES NO
A sample strategy:
Divide the deck in half and turn over all lower 50 cards, setting aside the highest number you find. Then turn over the other 50 cards, one by one, until you reach a number that is higher than the card you set aside: this is your chosen "high card."
Now, there is a 50% chance that the highest card is contained in the top 50 cards (it is or it isn't), and a 50% chance that the second-highest card is contained in the lower 50. Combining the probabilities, you have a 25% chance of constructing the above situation (in which you win every time).
This means that you'll lose three out of four games, but for every four games played, you pay $40 while you win one game and $50. Your net profit every four games is $10.
Obviously, you have to have at least $40 to start in order to apply this strategy effectively. Did you answer this riddle correctly?
YES NO
Lambs Goats Turkeys Scottish Field Riddle
You're standing in a Scottish field with green as far as the eye can see and you're standing alone. You check left, you check right and there's nobody anywhere. Out of the horizon the farthest distance away, comes three lambs. They come up to you and say hello. The first one says "My names Marley!", the second one says "My names Barley!", and the third one says "My names Richard!"
You say hello to each and then they go "baaah" and go right back to where they came from. On your left you see three goats approach you from the horizon. "Hello! My names Billy!", My names Jilly!", "My names Willie!" You say hello to each and then they go "baaah" and go back to where they came. On your right you see three turkeys approach you from the horizon. "Hello! My names Veronica!", "My names Maisel!", "My names Brittney!"
You reply hello to each and then they go "baaah" and go back to where they came. All is silent and then you start thinking whos gonna come up behind me? So you turn around.
What three animals approach from behind you and what are their names?
You say hello to each and then they go "baaah" and go right back to where they came from. On your left you see three goats approach you from the horizon. "Hello! My names Billy!", My names Jilly!", "My names Willie!" You say hello to each and then they go "baaah" and go back to where they came. On your right you see three turkeys approach you from the horizon. "Hello! My names Veronica!", "My names Maisel!", "My names Brittney!"
You reply hello to each and then they go "baaah" and go back to where they came. All is silent and then you start thinking whos gonna come up behind me? So you turn around.
What three animals approach from behind you and what are their names?
Hint:
Prisoner Hat Riddle
There is a wall between prisoners C and D (which cannot be seen through or around). Prisoner A can see prisoners B and C (by moving his head to the side). Prisoner B can see prisoner C. Prisoners C and D see only the wall.
The prisoners are immobilized in the ground and can't twist their body to see the person behind them. The warden shows them two black hats and two white hats and then puts the hats in a bag to conceal them. He then stands behind each prisoner, chooses a hat from the bag, and puts it on their head. The color of each prisoner's hat is shown in the image above.
The rules are simple. If any prisoner can figure out the color of the hat on his head, all four prisoners will be set free. But they must be sure, if one of them simply guesses and is wrong, they will all be shot dead! The prisoners are not allowed to talk to each other and they have 10 seconds.
The warden counts down "ten, nine, eight, seven". All four prisoners are silent. The warden smiles, knowing that he put the hats on in such a way that no prisoner could possibly know the color of the hat they had on. He continues "six, five, four, thr.."
"I know the color of my hat!" one of the prisoners finally blurts out.
Which prisoner called out and why is he 100% certain of the color of his hat?
Hint:
Prisoner B.
If prisoners B and C had the same color hat on, prisoner A would have know immediately that his hat was the other color (there are only two hats of each color). Since prisoner A was silent, prisoners B and C must have different colored hats. Prisoner B realized this and knew that his hat was not the same color as prisoner C, therefore his hat must be black! Did you answer this riddle correctly?
YES NO
If prisoners B and C had the same color hat on, prisoner A would have know immediately that his hat was the other color (there are only two hats of each color). Since prisoner A was silent, prisoners B and C must have different colored hats. Prisoner B realized this and knew that his hat was not the same color as prisoner C, therefore his hat must be black! Did you answer this riddle correctly?
YES NO
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