Originally posted by: sirjonk
4
14
11-14
31-14
13-21-14
What's the next in the progression?
You have 12 golf balls, 11 of the same weight and one of a deviating weight. You are allowed to use a balance scale 3 times. BUT, you do not know whether the deviating golf ball is heavier or lighter than the rest. Using the scale 3 times, you have to point out the deviating ball AND tell whether its heavier or lighter than the rest.
You are a prisoner in a foreign land. your fate will be determined by a little game. there are two jars, one with 50 white marbles, and one with 50 black marbles. at this point, you are allowed to redistribute the marbles however you wish (e.g. swap a black marble with a white marble, etc.): the only requirement is that after you are done with the redistribution, every marble must be in one of the two jars. afterwards, both jars will be shaken up, and you will be blindfolded and presented with one of the jars at random. then you pick one marble out of the jar given to you. if the marble you pull out is white, you live; if black, you die. how should you redistribute the marbles to maximize the probability that you live; what is this maximum probability (roughly)?
5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
Originally posted by: brikis98
Originally posted by: sirjonk
Some of the versions of this riddle I found limit the sun to <100, if that helps. Having read the answer, it wouldn't help me. Unless phrases like "of course, all even numbers can be expressed as the sum of two primes" roll off your tongue with ease, I suggest skipping.
It's an interesting riddle, because you definitely CAN see patterns and eliminate lots of possibilities... but it is WAY too much paper work to track it down to the final answer. I could prob write a computer program to simplify it... but, while I'm bored at work, I don't think i'm THAT bored
any1 else got interesting puzzles to post?
Originally posted by: sirjonk
http://www.puzzle.dse.nl/tease...ex_us.html#know_or_not
From this version it appears the info in the statements is slightly different, i.e. the first line is Product guy: "I don't know what YOUR sum is, Sum guy"
Originally posted by: Atomic Playboy
Originally posted by: brikis98
Originally posted by: sirjonk
Some of the versions of this riddle I found limit the sun to <100, if that helps. Having read the answer, it wouldn't help me. Unless phrases like "of course, all even numbers can be expressed as the sum of two primes" roll off your tongue with ease, I suggest skipping.
It's an interesting riddle, because you definitely CAN see patterns and eliminate lots of possibilities... but it is WAY too much paper work to track it down to the final answer. I could prob write a computer program to simplify it... but, while I'm bored at work, I don't think i'm THAT bored
any1 else got interesting puzzles to post?
No, seriously, why can it not be any combination of numbers? Suppose the numbers are 10 and 27. The conversation goes as follows:
Ann says "I know their product [270, but she doesn't tell Bob], but I I don't know what the two numbers are"
Bob says "I knew that you didn't know what the two numbers are. I don't know them either, but I know their sum [37, again, not telling Ann]."
Ann says "Based on what you told me, I now know what the two numbers are."
Bob says "And now based on what you told me, I now know what the two numbers are."
Ann guesses 9 and 30, Bob guesses 13 and 14, they're both wrong. Where's the riddle?
Originally posted by: Kyteland
You have 12 golf balls, 11 of the same weight and one of a deviating weight. You are allowed to use a balance scale 3 times. BUT, you do not know whether the deviating golf ball is heavier or lighter than the rest. Using the scale 3 times, you have to point out the deviating ball AND tell whether its heavier or lighter than the rest.
Measure 5 vs 5. If they're even, measure the two not used. If one set of 5 is heavier, measure 2 vs 2. If they're even , the one left out is the different one. Otherwise, measure among the 2 that's heavier.
Edit: hmm just realized you dont know whether it's heavier or lighter... That stumps me
You are a prisoner in a foreign land. your fate will be determined by a little game. there are two jars, one with 50 white marbles, and one with 50 black marbles. at this point, you are allowed to redistribute the marbles however you wish (e.g. swap a black marble with a white marble, etc.): the only requirement is that after you are done with the redistribution, every marble must be in one of the two jars. afterwards, both jars will be shaken up, and you will be blindfolded and presented with one of the jars at random. then you pick one marble out of the jar given to you. if the marble you pull out is white, you live; if black, you die. how should you redistribute the marbles to maximize the probability that you live; what is this maximum probability (roughly)?
One white marble into one jar. 49 White and 50 black into the other. Chance of survival should be around 74.9 ish
98 0 1 1 0 or 98 0 1 0 1 works as well5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
Originally posted by: Atomic Playboy
Originally posted by: brikis98
Originally posted by: sirjonk
Some of the versions of this riddle I found limit the sun to <100, if that helps. Having read the answer, it wouldn't help me. Unless phrases like "of course, all even numbers can be expressed as the sum of two primes" roll off your tongue with ease, I suggest skipping.
It's an interesting riddle, because you definitely CAN see patterns and eliminate lots of possibilities... but it is WAY too much paper work to track it down to the final answer. I could prob write a computer program to simplify it... but, while I'm bored at work, I don't think i'm THAT bored
any1 else got interesting puzzles to post?
No, seriously, why can it not be any combination of numbers? Suppose the numbers are 10 and 27. The conversation goes as follows:
Ann says "I know their product [270, but she doesn't tell Bob], but I I don't know what the two numbers are"
Bob says "I knew that you didn't know what the two numbers are. I don't know them either, but I know their sum [37, again, not telling Ann]."
Ann says "Based on what you told me, I now know what the two numbers are."
Bob says "And now based on what you told me, I now know what the two numbers are."
Ann guesses 9 and 30, Bob guesses 13 and 14, they're both wrong. Where's the riddle?
Originally posted by: Mo0o
98 0 1 1 0 or 98 0 1 0 1 works as well5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
Originally posted by: merlocka
The last guy has a 50-50 to live.
But he counts the remaining hats. If it's even, he says red. If it's odd, he says black.
The second guy counts the hats. He knows what color he has. He then repeats the above.
98% survival rate.
This was in CS101, it's a parity check.
Originally posted by: sirjonk
Originally posted by: Mo0o
98 0 1 1 0 or 98 0 1 0 1 works as well5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
Why would 3 of 5 robbers vote to approve that breakdown?
Originally posted by: JTsyo
Originally posted by: brikis98
ok, one more puzzle from me. after this, someone else please post something interesting for us to figure out
In your laboratory, you are mixing up a huge batch of very dangerous chemicals. The reaction is so dangerous, that if you don't do your job properly, it will explode and take out a 50 mile radius. Fortunately, your job is simple. You have two chemicals - chemical A and chemical B - which come in the form of small sticks. All you have to do is toss in exactly 1 stick of chemical A and 1 stick of chemical B every ten minutes. The reaction lasts 100 minutes, so you have 10 sticks of each chemical. Unfortunately, your foolish lab assistant dropped all 20 sticks on the floor, and they all got mixed up! Worse yet, chemical A and B are virtually indistinguishable: they look, taste, smell, feel, and weigh the same!
The question: what strategy can you use to be sure to toss in exactly 1 stick of each chemical every 10 minutes for 100 minutes? Remember, if you put in too little during a 10 minute interval, you die. If you put in too much, you won't have enough alter, and you die.
Split them into two piles and call black when you toss them in?
You have two ropes. Each takes exactly 60 minutes to burn. They are made of different material so even though they take the same amount of time to burn, they burn at separate rates. In addition, each rope burns inconsistently, so half way mark on each rope does not represent 30 minutes. How do you measure out exactly 45 minutes?
You have 12 golf balls, 11 of the same weight and one of a deviating weight. You are allowed to use a balance scale 3 times. BUT, you do not know whether the deviating golf ball is heavier or lighter than the rest. Using the scale 3 times, you have to point out the deviating ball AND tell whether its heavier or lighter than the rest.
You are a prisoner in a foreign land. your fate will be determined by a little game. there are two jars, one with 50 white marbles, and one with 50 black marbles. at this point, you are allowed to redistribute the marbles however you wish (e.g. swap a black marble with a white marble, etc.): the only requirement is that after you are done with the redistribution, every marble must be in one of the two jars. afterwards, both jars will be shaken up, and you will be blindfolded and presented with one of the jars at random. then you pick one marble out of the jar given to you. if the marble you pull out is white, you live; if black, you die. how should you redistribute the marbles to maximize the probability that you live; what is this maximum probability (roughly)?
5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
Originally posted by: Mo0o
Here's an easy one:
You have two ropes. Each takes exactly 60 minutes to burn. They are made of different material so even though they take the same amount of time to burn, they burn at separate rates. In addition, each rope burns inconsistently, so half way mark on each rope does not represent 30 minutes. How do you measure out exactly 45 minutes?
Originally posted by: Kyteland
Say you have a sheet of paper, what is the maximum number of pieces you can cut it into given n cuts. You cannot fold the sheet or rearrange already cut pieces (i.e., even after the nth cut, the pieces remain in the same position as they were before any cuts were made.)
And if you really want to geek out generalize the problem to any dimension. You have a X dimensional shape. You cut it N times in the X-1 dimension without moving or rearranging the pieces. How many pieces do you have?
Originally posted by: brikis98
5 robbers hold up a diamond store and make out with 100 diamonds, all of equal value. Instead of splitting the diamonds equally among them, they decide that they will have a bidding contest with these rules:
- Each robber draws a number out of a hat (1, 2, 3, 4 or 5)
- Starting with the smallest number, each robber will have the chance to make a proposal on how to best split the diamonds. Eg, 20-20-20-20-20 or 0-10-20-30-40 are possibile bids.
- Each robber votes on whether to accept the proposal and if there is a majority (>50% vote yes) it passes.
- If is does not pass then the robber who proposed it is killed and the process is repeated with the remaining, smaller group.
- Each robber is assumed to be equally smart and will veto any proposal when they know they can do better.
What should the first robber bid to keep themselves alive and to maximize their diamonds?
I believe you have an error in your problem. I've solved an almost identical one before with 5 pirates splitting 100 gold coins. The only difference there was that each pirate needed greater than or equal to 50% to get his vote to pass. If you only have greater than, you run into ambiguous scenarios.
For example, take the same problem, but with only two robbers, D and E, with D proposing first. If D needs greater than 50% of the vote, he knows he can't make a proposal where he gets ANY diamonds, or E will vote it down. What isn't clear, however, is if E would vote down the distribution where D gets 0 and E gets 100. There's no reason to assume E would want D's death since his desire is only to earn diamonds. However, this is very important as it can impact the final solution. That is, if D knows he will ALWAYS die in a 2 person scenario, when we discuss a 3 person scenario (C, D, E), he would vote for ANY proposal of C's as it would let him live. Otherwise, if D always lives in a 2 person scenario, but with no diamonds, C must offer D 1 diamond to secure his vote in a 3 person scenario. These same ambiguities go all the way up to the 5 person scenario and you end up with multiple possible answers.
If we solve the *proper* problem (with greater than or equal), we get:
D, E
D would propose a distribution of 100, 0 and since he needs only needs 50% of the vote to pass, his own vote pushes it through.
C, D, E
C knows that in a 2 person scenario, E gets nothing. So, he offers E one diamond for his vote, or a 99, 0, 1 distribution.
B, C, D, E
B knows that in the 3 person scenario, D gets nothing. So he offers D one diamond for his vote, or a 99, 0, 1, 0 distribution. Again, they need just 50% to pass, and this will work.
A, B, C, D, E
A knows in that in the 4 person scenario, C and E get nothing. He therefore offers them just one diamond, or a 98, 0, 1, 0, 1 distribution.
Originally posted by: QED
Ok... another oldie:
Given a standard 8-by-8 chessboard with two opposing corner squares removed and a stack
of 2-by-1 domino pieces, is it possible to cover the entire chessboard using the domino pieces
without any overlaps? Each half (a square) of each domino must cover exactly one square on the chessboard,
and each square on the chessboard must be covered. If so, how?
Originally posted by: CPA
I'm not good at these, but I have one. Probably too simple, though.
Picture a chocolate cake and a cake knife. You need to cut the cake into eight pieces with only three slices with the knife. How do you do it?
