Please help make the world a better place by contributing "real riddles," i.e. not trivia or tricks.
Here is my contribution and if you're inclined to forward good riddles, I'll be happy to post them.
Some folks object to the use of the word "Riddle" on this page, claiming riddles are not logic problems or brain teasers. Some of these riddles are definitely in the deductive reasoning department and there aren't many poems (ala Bilbo etc.). But if you think none of these riddles requires insight, wit, or creativity, then solve "Three Dots," "Auction Action," "Enlightenment," and "Sailor's Delight" then you'll have earned the right to whine :-)
p.s.: Not infrequently a person will send email asking for answers. Not infrequently the reply is, "I would hate to rob you of the privilege and pleasure of solving them."
If you are thinking about writing, read the next note.
If you are still thinking about writing, read the Riddle Page Philosophy.
If you are still thinking about writing, then you must not be able to read, so this paragraph won‘t help you any.
Up until recently, you could send your solutions and I would tell you whether they were "correct," but traffic has increased to the point that the only riddle I‘ll check for you is River City.
p.p.s.: Just in case you were wondering whether there are any hints for these riddles... there aren‘t! You have all the information necessary to solve them.
p.p.p.s.: You would not believe the crazy things people make up to try to weasel out answers and hints. Sadly... (and let us pause for a moment of silence here...) none are successful at weaseling!
p.p.p.p.s.: Some weaselers write and say, "I will help you
answer my super-duper-difficult riddle if you give me the answer to
your riddle X." Then, if I don‘t respond, they write and say, "See, I
knew you were not very smart, because you didn‘t figure out my riddle,
and you didn‘t figure out all your own riddles, so there! Now you
have to tell me your answers, you loser."
To you I say, "Get a Life" and then read Riddle Page Philosophy.
p.p.p.p.s.: None of these riddles is original - they were told to me as a young impressionable child and (twitch) didn‘t (twitch) affect (twitch) me (twitch) at all. Some were sent via email and I asked the senders for permission to post.
If you write, start the subject line with "riddles:". That way my mail filter can weed it out, er... I mean... file it in the appropriate file.
p.p.p.p.p.s: And as Bill Clinton so clearly explains, "I suppose it depends on what your definition of "is" is."
p.p.p.p.p.p.s: And as Vice Perpetrator Al Gore so believably explains, "I believed him."
|Three Dots||Open Door Policy||Lying Defeeted||Tractor Beam|
|Hat-trick||Trouble in River City||No Vacancy||Enlightenment|
|Three‘s a Crowd||Timing is Everything||No Vacancies||Ashpynxiated|
|Auction Action||Light Bridge||Apairantly Not|
|Ties that Bind||Flight Plight||Sailor‘s Delight||Heads Up|
|Hats Off||Lazy Susan||Eat and Run|
|Links to Riddles|
You are travelling in a deep, dark forest when, suddenly, on a dark and stormy night, you are captured by the kind-but-not-so-bright forest people. They keep looking at you and saying to each other, "It be a smart person!"
You are marched to their village and seated in the square. Before you are blindfolded, you notice two other lucky souls seated in chairs facing you. Then you are told that the forest people king is about to die. He previously sent messengers throughout the land seeking the 3 smartest people. You are one, and two others have also been found. He now gives you all a task to see which one is the wisest.
He tells you, "I have seated you in an equilateral triangle so that each of you faces the other two. While you are blindfolded I will paint a dot on each of your foreheads. Each dot will be red or green so that there can be any combination of red and green dots, for example, 1 red and 2 greens, or all red, etc. When I remove the blindfolds each of you must raise your hand if you see _any_ green dots, i.e. 1 or 2 dots. As soon as you have figured out what color your own dot is, tell me how you knew."
So he paints a green dot on all three foreheads. When the blindfolds are removed, all three hands go up. After a long pause, the wisest person, (that‘s you!) say, "Your highness, I have a green dot. The reason I know this is that..."
How did you know?
Extra credit: assume there are 4 people and all have green dots... can our hero figure it out now?
Note: please don‘t write,
Sadly, every one of the above sentences was sent to me as a possible solution!
After solving the riddle of the three
wise folks, three scoundrels claim to be the smartest in
the country. So you decide to give them a challenge.
Suspecting that the thing they care about most is money, you
give them $100 and tell them they are to divide this money
observing the following rule: they are to discuss offers and
counter-offers from each other and then take a vote.
Majority vote wins.
Sounds easy enough... now the question is, assuming each person is motivated to take the largest amount possible, what will the outcome be?
Note: careful... if the answer were that they split it 50% / 50% / 0%, or 1/3 / 1/3 / 1/3, it wouldn‘t be a riddle!
Note: careful... 96.6523544 % of people who send answers to this have not thought about it for even 1 minute. I guarantee you won‘t solve it in a minute. (96.6523544% of the time this guarantee is correct.)
After being the ruler of the forest people for a while, you get bored. So you visit an island on which two tribes of natives live. One tribe has purple soles and always lies; the other tribe has green soles and always tells the truth. There are three natives standing near you. You can‘t see the bottoms of their feet, and indeed you find out it is rude to look at another‘s soles, but you are curious so you ask the first man,
"Sir, what color are your soles?" Now he happens to understand English, but he can‘t speak it, so he replies in his native tongue, "Glub Glub". Though you don‘t speak the language, you know that "Glub Glub" either means purple or green.
You turn to the second man and ask, "Sir, what did he say?" The second man replies, "He said he has green soles."
Now to be sure, you turn to the third and ask, "Sir, what color of soles does this second man have?" The third man replies, "Sir, he has purple soles."
Now the question is, what color of soles does the third native have?
On your trip back from the Island people to the deep dark forest, you get lost. A trap door suddenly opens and you fall down into a dark chamber.
You hear a voice, "You are trespassing and the penalty is death. In five minutes you will be buried alive. However due to our exceeding kindness and mercy, and because you were once ruler of the forest people, we will allow you to earn your life back. In this dark chamber there are two doors. You may choose to open either one - if you choose correctly, you will go free. If you choose incorrectly, well, instead of just being buried alive, you will be eaten alive by army ants.
To help you choose a door, you may ask a question. However, you should know that two people will hear you and one of them always lies and the other one always tells the truth. One of them will answer your question, but you will not know which one. Each of them knows which door leads to freedom.
Good Luck, you have four and a half minutes left."
What question do you ask to win your freedom? (At least two solutions.)
After asking which door he would send his Mother-In-Law through and choosing the other one (Open Door Policy), you are allowed to walk through the Door of Freedom. After taking a few deep breaths of fresh air, you set out to escape this deep dark forest. As fate would have it, you feel a thud on your noggin and wake up in a dimly lit room with a pool table. You are about to be challenged to a game of 9-ball when the wicked forest people notice chalk on your hand. Wary of the possibility of you turning out to be a pool shark, they give you this challenge instead.
On the pool table are 12 balls of identical size. And all are of identical weight except possibly one, which is either slightly heavier or slightly lighter than all the others, but not enough for you to be able to tell just by holding it. So you don‘t know whether they all weigh the same, or whether there is one odd one. And if there is an odd one, you don‘t know whether it‘s light or heavy.
Now the evil forest people bring a balance scale so that you may compare objects against each other. "No problem" you‘re thinking. "I‘ll just compare them to each other to find the exception." However, you are then informed that you may only use the scale three times.
How do you use the balance scales so that in just three comparisons, you determine they all weight the same, or find the one suspicious ball and know whether it is heavier or lighter?
After figuring out how to use the scales just three times to find the odd ball, you are released back into the forest. You are walking along minding your business when a snare suddenly grabs your foot and yanks you upside down 30 feet off the ground. When you stop swinging you realize you won‘t be able to just climb up the rope, because you are right beneath a large platform with no holds on the bottom. You examine the rope and see that there is no way to untie it.
"If only I had a knife..." Then you notice slight movement at the underneath edges of the platform and see that the movement is actually thousands of army ants beginning to move down over the platform to the underside and towards you. They look exceedingly hungry. They don‘t look like vegetarians.
When things look hopeless, you notice a sphynx couple sitting on a huge branch. One of them throws a knife into the air and when it comes back down, they both reach for it. You cannot tell which one actually grabbed it. All you know is that you need that knife to cut yourself down.
The husband says "The sphynx with the knife always tells the truth." But the wife counters, "He‘s wrong, the sphynx with the knife always lies." As luck would have it, one of them always lies and one of them always tells the truth. Using only these two statements as data, you get one chance to guess who has the knife.
The ants are approaching, who has the knife?
Note: please don‘t just say, "The Wife/Husband has it!". Say _why_.
After calmly figuring out who had the knife, you cut the rope just as an army ant reaches it. You are lucky and fall into a pile of leaves, bounce up and land in a chair. As you start to look around you hear a stearn voice say, "Eyes forward!" (some of you have heard that voice!)
There are two people sitting behind you, so there are three people facing the same direction. The other two are the two smartest people in the forest (a scary thought). There are five hats: three are red and two are purple.
While all of your eyes are closed, a hat is placed on each person‘s head and the two unused hats are hidden. Then all are allowed to look only forward so that each of you can only see the people in front of you (the person in the back can see the hats of the two people in front; the middle person can see your hat; you can‘t see any hats at all; so you might as well keep your eyes closed!)
When someone figures out what color hat they are wearing, they must call out. No one has called out yet. What color hat are you wearing and how do you know?
After you figure out that you were wearing a Cowboy hat all along, (Hat-Trick) you decide to go home. Unfortunately you must take an old, old bridge across a deep, dark chasm. It is dark and there are so many steps missing that you ask to borrow a flashlight. Three forest people approach and offer you a flashlight in return for helping them across the bridge. Now the bridge allows a maximum of 2 people at once and for safety, there must always be someone on the bridge holding a flashlight (of which there is only 1). In addition, the three forest people take 2, 5, and 10 minutes respectively to cross the bridge. You, being highly motivated, need only 1 minute.
No problem, you think, we‘ll just take turns walking folks back and forth with the light until we‘re all across. But the bridge is enchanted and every million years, it vanishes for a century and that will happen in exactly 17 minutes.
How will all four of you make it to the other side of the bridge in 17 minutes?
(Note: Call these people #1 #2 #5 and #10. If you and
#10 go across and you return, that takes 11 minutes. Then
you and #5 could go across and you return; we are now up to
17 minutes... *poof* - bridge is gone.
The light carrier doesn‘t have to be you. If the light carrier is accompanied by anyone, they must stay together the whole way across - you cannot have one person stand in the middle and shine the light. No piggy-backs, no simultaneous-2-way-crossings, etc.)
After barely making it across the bridge, you hear two of the forest people arguing. It seems that just before they crossed the bridge, they each bought 10 pair of socks, and in fact, as far as color and size go, they each bought the same exact 10 pairs. Each person has 1 pair of green, 1 pair of blue, etc. etc... But now they have accidentally dropped all their socks and the socks are all mixed up in a pile on the ground.
Because it is pitch-black, they can‘t see what colors the socks are, but want to divide them up so that they each have the same colors that they bought, i.e. identical sets of green, blue, etc. Luckily the socks are all still in pairs, so they only have to pick up 20 pairs, not 40 individual socks.
The light used in crossing the bridge fell into a bottomless forest pit, so even though it is pitch-black, how can you help the two forest people get one pair each of every color, just like they had before they dropped them?
(Note: no lights, moon, cigarette lighter, etc...)
You watch the sock-hoppers amble off toward a pier and notice a small island about a mile away from shore. Due to your excellent forest vision, you see a Forest person plowing a field with a large tractor. There are no bridges or tunnels to the island and you wonder how the tractor got out to the island.
"That‘s a good question," says a nearby forest person, reading your mind. "I have the only boat around here and it‘s not big enough to carry that tractor over. I didn‘t drop off any parts either so he couldn‘t have built it there. No one has an airplane or helicopter to drop it off either."
So how did the tractor get on the island?
1. the tractor was not built on the island
2. even with tides, the water is too deep to drive across
3. it was not driven across the bottom of the ocean or under water
4. it was not disassembled)
After using the same method that the tractor took to get to the Island, you drop in on a party of the forest people and notice Prof. Chaos with an evil look in her eye. Folks look bored, so she decides to engage in a little mischief. "I will give this $100 bill to the highest bidder. The only rule is that the person who bids the second highest amount will also have to pay me that bid. The highest bidder pays the high bid and takes the bill, even if the highest bid is only 5 cents."
People start to murmur. Then you hear "A nickel!". "A Dime!". "Two Dollars!"...
Question: what is Prof. Chaos up to?
In the forest, a hotel has an infinite number of rooms. An infinite number of forest people arrive and each takes a room. So far so good. Now you would like a room.
Can the hotel accomodate you? If so, how?
(Please enjoy this riddle instead of writing that infinity is the same as infinity plus 1 or some such gibberish! Folks who send me stupid definitions ("Infinity is, you know, like never ending, so, like, sure, they‘d all have rooms, you know, like duh.") are almost without exception the least knowledgeable about infinity! So have fun with it; ask yourself what you‘d do if you were the inn-keeper. However, you must find _rooms_ for everybody, no doubling up, sleeping in the kitchen etc.)
The hotel has an infinite number of rooms. An infinite number of forest people arrive and each takes a room. So far so good. Now another infinite number of guests arrive.
Can the hotel accomodate them all? If so, how?
(see the note above on "No Vacancy")
A Beanie Baby named Joe comes home from work by train every
day. He gets to the train station at 5 pm and from there
his dog picks him up in the car. One day Joe arrived at the
station at 4 pm and decided to start walking and meet his
dog somewhere between the train station and home. His dog
drove the car as usual; met him on the road before reaching
the station, and took him home.
That day, they got home 20 minutes earlier.
Question: How long had Joe been walking?
(Tips: not 20 minutes; not 40 minutes; of course beany babies can drive; and if beany babies can drive, well, then so can their dogs.)
Strolling through the forest, you hear a muffled shout. Investigating further, you come to a closed, solid, light-proof door. "... need Light! Light!..." you can barely make out coming through the door.
"Use the switches to know which one controls the Light!" you hear the voice say as you notice three on/off switches beside the door.
Inside the cave is an incandescant lamp which is now off. Next to the door are three switches. One of these three switches turns the lamp in the room on and off.
Your job is to figure out which switch controls the lamp. However, you can‘t just open the door and look. In fact, you can only enter the cave one time and then you have to say which switch controls the lamp. There are no windows, holes, cracks, leaks, bleeding-heart-liberals, etc. You are allowed to set any switches on or off and then enter the cave. That‘s it.
What will you do to know with certainty which switch controls the lamp?
Extra credit: what if there are 4 switches?
After discovering it was the third switch which controlled the light
(wasn‘t it just so obvious), you see a forest person carrying a sign which
reads, "The Time has Come!"
"What time?" you ask.
"The time to tell you about the String Problem," he answers and then starts to shout, "45! 45! 45!"
You reply, "Caliber?"
"No... Minutes! You need 45 minutes! and all we have are these two strings!"
You have 2 long strings which burn at random rates at different positions on their length. Though they are not identical, they do burn exactly 1 hour each. A string might burn 99% of it‘s length in 1 minute, then take 59 minutes to burn the rest of the way.
You have no way of telling time; clock, watch, sunset, etc. but need to measure 45 minutes.
Using these string and a lighter, how can you measure 45 minutes?
On Tractor Island, there is an airport. The airport is the homebase of an unlimited number of identical airplanes. Each airplane has a fuel capacity to allow it to fly exactly 1/2 way around the world, along a great circle. The planes have the ability to refuel in flight without loss of speed or spillage of fuel. Though the fuel is unlimited, the island is the only source of fuel.
What is the fewest number of aircraft necessary to get one plane all the way around the world assuming that all of the aircraft must return safely to the airport?
After flying around the world and touching down on Tractor Island, you‘re thirsty from the long flight. You walk over to the pop machine and realize you have no quarters.
Then you notice a line of quarters right there on the ground. The line goes on and on, clear into the forest. "There must be thousands of them!" you exclaim.
"Infinite, to be exact." says the voice of an evil
forest person. "And you can have them all if you divide
them into two piles which have the same number of heads."
"How much time do I have?"
"1 day. You can pick up as many quarters as you want and even flip them over, just as long as you wind up with two piles that have the same number of heads. I happen to know that there are 20 heads, the rest are all tails."
"Do the piles need to have the same total number of quarters?" you ask observantly.
"No, just the same number of heads. If you‘re ready to begin, here‘s the blindfold."
"The one you have to wear while solving this riddle!"
Question: Given infinte coins,
10 pirates are ranked in order, first to last. After finding a treasure chest of 100 gold coins, they are discussing how to divide up the booty. They allow the lowest ranked sailor to divide up the coins and then vote on his idea. If the number of pirates who like the division is equal to or greater than the others who don‘t like it, then the boss will say, "Make it So." (The proposer of the idea also has a vote.)
Otherwise... well, being pirates their simple solution is to dump the unfortunate sailor into the deep blue sea and let the next pirate in line decide how to divide up the spoils.
Question: How many pirates will be thrown into the sea?
Three players enter a room and a red or blue hat is placed on each person‘s head.
The color of each hat is determined by a coin toss, with the outcome of one coin toss having no effect on the others. Each person can see the other players‘ hats but not his own.
No communication of any sort is allowed, except for an initial strategy session before the game begins. Once they have had a chance to look at the other hats, the players must simultaneously guess the color of their own hats or pass. The group shares a hypothetical $3 million prize if at least one player guesses correctly and no players guess incorrectly.
The same game can be played with any number of players. The general problem is to find a strategy for the group that maximizes its chances of winning the prize.
One obvious strategy for the players, for instance, would be for one player to always guess "red" while the other players pass. This would give the group a 50 percent chance of winning the prize.
Question: Can the group do better than 50%?
Placed in front of you is a "Lazy Suzan" with four shot glasses placed equally apart around the outer edge. They have been randomly placed either right side up or upside down and it is your challenge to get them all oriented the same way; that is, either all four up, or all four down, as quickly as possible.
Of course you will be blindfolded! You‘re not surprised...
Each turn the Lazy Suzan will be spun and you may then touch any two glasses, and then decide to keep each as it is or turn either one, or both, over. OK?
You may keep both that you touch the same, turn them both over, or turn just one of them over (your choice, either one). Obviously, as you reach down to grab two of the glasses you will be able to tell which two of the four you are touching - both in front of you; both away from you; the two on the left; the two on the right; or either of the two corner to corners.
You will start with a $10,000 Prize Fund which will be decreased by $1,000 after each turn. I will stand next to you and announce after each of your efforts as to whether or not you have solved the puzzle. Of course, there‘s no chance in the whole world that you will be so lucky as to start with all four in a winning position, but of course you already knew that. And also, if you decide to rely on luck to get you to the final solution you should understand that once the $10,000 Prize fund is gone, you will then have to start paying $1,000 for each wrong guess you make from then on out - No Stopping until you get it right!
Question: What process can you use to guarantee success?
Twenty mathematicians are captured by cannibals who want to eat the mathematicians, but they‘re sporting cannibals who are willing to give the mathematicians a chance to save themselves.
So, they tell them that they will be lined up, single file, and have either a black or white hat placed on their head. Starting with the last mathematician in line and working toward the front, each will be asked to name which color hat he‘s wearing. If correct he‘s set free, and of course, if wrong he‘s an entree. No communication of any sort is allowed, except for an initial strategy session before this all begins, and then the announcement of which color hat each is wearing.
Question: How many of the mathematicians can be saved?
|Contact firstname.lastname@example.org||Copyleft 1997-2019 Brent Neal Reeves||Last edited: early 21st Century|