Search found 22 matches

by Pelli
Sun Sep 14, 2014 11:35 am UTC
Forum: Logic Puzzles
Topic: Tournament Scheduling
Replies: 6
Views: 3208

Re: Tournament Scheduling

One interesting sub-question is: Ignoring games completely, and forgetting the labels on people and times, how many genuinely different schedules are there? I.e. in how many genuinely different ways can 6 people be scheduled to meet pairwise in five time slots so that each person meets every other e...
by Pelli
Fri Aug 29, 2014 7:55 am UTC
Forum: Logic Puzzles
Topic: Hard number sequence: 4, 8, 16, 26, 41, 57, 79, 104, 138,...
Replies: 16
Views: 8124

Re: Hard number sequence: 4, 8, 16, 26, 41, 57, 79, 104, 138

A compromise between the line breaks being important and purely cosmetic is if they are hinting at the Fibonacci sequence (5, 3, 2, 1, 1). EDIT: Also, continuing PsiSquared's note : The ratio between successive terms is 2.00000, 2.00000, 1.62500, 1.57692, 1.39024, 1.38596, 1.31646, 1.32692, ...
by Pelli
Thu Aug 28, 2014 9:27 am UTC
Forum: Logic Puzzles
Topic: Illustrated Math Function
Replies: 8
Views: 8545

Re: Illustrated Math Function

An obvious guess for a bit of manipulation of the second image is
Spoiler:
It's the negative (and possibly half?) of the original, so -gamma or -gamma/2.
by Pelli
Wed Aug 27, 2014 10:55 am UTC
Forum: Logic Puzzles
Topic: Hard number sequence: 4, 8, 16, 26, 41, 57, 79, 104, 138,...
Replies: 16
Views: 8124

Re: Hard number sequence: 4, 8, 16, 26, 41, 57, 79, 104, 138

I would expect the formatting into rows to be significant, and possibly a hint that a row is missing.

Is it just a coincidence that...
Spoiler:
57 + 79 = 136 = 138 - 2
79 + 104 = 183 = 184 - 1
and perhaps
104 + 138 = 242 = 241 + 1
?
by Pelli
Tue Aug 26, 2014 1:03 pm UTC
Forum: Logic Puzzles
Topic: Illustrated Math Function
Replies: 8
Views: 8545

Re: Illustrated Math Function

My thoughts: The first image is 0 The second image somehow involves x? Though I guess its supposed to be a number. I'm pretty sure this is an x-ray of a large truck. Maybe 18 (for 18 wheeler)? The third images is either pi^2 or pi/6 Just getting the juices flowing Interesting observatio...
by Pelli
Mon Aug 11, 2014 12:32 pm UTC
Forum: Logic Puzzles
Topic: 5 word puzzle
Replies: 3
Views: 2812

Re: 5 word puzzle

Here's what I've noticed. Words seem to reuse three of the letters that occur in the word preceding them. The exception is the last word, which reuses only one (S). All those letters that occur more than once are reused in this way in multiple sequential words. This is all I have found for ...
by Pelli
Sat Aug 02, 2014 9:38 am UTC
Forum: Logic Puzzles
Topic: Two interesting puzzles (1 easy, 1 unsolved)[Solutions,etc.]
Replies: 5
Views: 4796

Re: Two interesting puzzles (1 easy, 1 unsolved)[Solutions,e

Not sure if relevant, but I recognise the first three three-letter combinations as... ...airport codes ARN - Stockholm (Arlanda) BCN - Barcelona ZRH - Zurich And the remainders would be KRT - Khartoum CPT - Cape Town BTS - Bratislava RUH - Riyadh DKR - Dakar Perhaps drawing lines between the cities ...
by Pelli
Sat Aug 02, 2014 9:04 am UTC
Forum: Logic Puzzles
Topic: Need help with a puzzle "InTerCoMMuniCaTiOns AlPhabEt"
Replies: 2
Views: 2137

Re: Need help with a puzzle "InTerCoMMuniCaTiOns AlPhabEt"

Nice! I'm quite sure this is the answer:

Spoiler:
The intercommunications alphabet is morse code.

Spoiler:
and parsing the rows in the obvious way yields CAPITAL CUE, i.e. Q
by Pelli
Sat May 19, 2012 11:51 am UTC
Forum: Logic Puzzles
Topic: Knights and Knaves Revisited
Replies: 5
Views: 2977

Re: Knights and Knaves Revisited

There are x knights, y knaves, and z randoms (that all know what each other are). The randoms just randomly say yes or no. You are given x,y,z, and you need to find out who is who in the minimum amount of questions. Also, if there are enough randoms, then it is possible that the problem is unsolvab...
by Pelli
Fri May 18, 2012 6:52 am UTC
Forum: Logic Puzzles
Topic: Knights and Knaves Revisited
Replies: 5
Views: 2977

Re: Knights and Knaves Revisited

Do the knights (and knaves) know knights from knaves? I would guess so, or else you can only gain information about the person you're asking and hence you need to ask N-1 people. Given this, it seems there's this solution: Use a wrapper such as "If I asked you X, what would you answer?&quo...
by Pelli
Thu Mar 29, 2012 9:20 pm UTC
Forum: Logic Puzzles
Topic: The Disgruntled Alien Visitor
Replies: 9
Views: 5297

Re: The Disgruntled Alien Visitor

We could be more efficient if we could figure out how to find out answers to our questions without knowing which of the three responses are which. Then we don't need to waste two questions at the beginning. E.g. if the possible responses are da/ja meaning yes/no then asking "Is it true that...
by Pelli
Tue Sep 27, 2011 8:45 am UTC
Forum: Forum Games
Topic: Solve this Mathematical Puzzle
Replies: 36
Views: 4573

Re: Solve this Mathematical Puzzle

I am posting the answer to this puzzle. The answer is 6480. After this if you cant calculate, I will give you the calculation. Since "6 + 5 + 1" = 6480 = 2^4 * 3^4 * 5, I'd guess it's "a + b + c "= a^(b-c) * b So it was only a coincidence that c = a^(b-c-1) in th...
by Pelli
Wed May 25, 2011 7:10 pm UTC
Forum: Logic Puzzles
Topic: Chain of Circles
Replies: 15
Views: 5954

Re: Chain of Circles

I think I have a solution: By rotational symmetry of circles, the optimal placement is to have all centres on a line. If circle #n has radius r n and distance d n to the next circle (between centres), then we have the relationship r n 2 = d n 2 + r n+1 2 . Hence we have 1 = r 0 2 = d 0 2 + d...
by Pelli
Tue May 24, 2011 10:49 pm UTC
Forum: Logic Puzzles
Topic: Humans and zombies - a knights-and-knaves style puzzle.
Replies: 3
Views: 2039

Re: Humans and zombies - a knights-and-knaves style puzzle.

Simpler, less general, solution for first bit: 1. Are you telling the truth? HT: (Yes) Yes HL: (No) Yes ZT: (Yes) No ZL: (No) No Alternative phrasing of undecim's general solution: You are human XOR you are telling the truth XOR statement Q ? HT: (Yes XOR Yes XOR ...
by Pelli
Fri Apr 29, 2011 7:40 pm UTC
Forum: Logic Puzzles
Topic: How many prisoners?
Replies: 112
Views: 46178

Re: How many prisoners?

Here is a strategy my friend came up with, which solves the problem with probability 1 (so only "almost surely") provided each prisoner has a random number generator: First, find an upper bound B for the number of prisoners, as described earlier. We also use the method to "ping" ...
by Pelli
Mon Apr 25, 2011 3:49 pm UTC
Forum: Logic Puzzles
Topic: How many prisoners?
Replies: 112
Views: 46178

Re: How many prisoners?

Assuming the e-mail cannot name specific prisoners, so that they all use the same strategy: Even if the strategy contains randomness, there is always a non-zero chance that up to day k, all prisoners have done the exact same thing. So no matter what strategy, they will not in finite time be able to ...
by Pelli
Sun Mar 20, 2011 9:19 am UTC
Forum: Logic Puzzles
Topic: Infinite Clones
Replies: 66
Views: 7356

Re: Infinite Clones

The answer may depend on whether we regard the cloning process as preserving the activator and creating a copy of him, or splitting him into two identical copies. In the first case, we could try to argue that only clones which have been "created" at some point count. This corresponds to re...
by Pelli
Fri Apr 16, 2010 11:47 am UTC
Forum: Logic Puzzles
Topic: Is This Even Possible?
Replies: 77
Views: 26992

Re: Is This Even Possible?

Proof of impossibility for unknown comparable words with random answering yes/no randomly: Let the words for yes and no be X < Y. There are eight answer strings, out of which two are indistinguishable: XXX=YYY. These must be assigned to 6 cases. There is nothing to compare the first answer to, so it...
by Pelli
Wed Apr 14, 2010 2:33 pm UTC
Forum: Logic Puzzles
Topic: Is This Even Possible?
Replies: 77
Views: 26992

Re: Is This Even Possible?

I don't believe that argument is correct. The first question may not provide us with any immediate information, but we may learn enough from the other two questions to go back and interpret that first answer. What I'm saying is that any deterministic algorithm will be of the following form (in PHP)...
by Pelli
Tue Apr 13, 2010 8:39 pm UTC
Forum: Logic Puzzles
Topic: Is This Even Possible?
Replies: 77
Views: 26992

Re: Is This Even Possible?

Didn't Nitrodon prove it's impossible when you don't know the words ahead of time? About the second case: The first answer gives no information beyond identifying one word for yes or no. The yes/no words can be described as "the answer given to the first question" and "the answer not ...
by Pelli
Fri Jun 26, 2009 11:52 am UTC
Forum: Logic Puzzles
Topic: Yet another hat problem
Replies: 10
Views: 2557

Re: Yet another hat problem

When I was first presented with this problem, I was given a sight of 3, and my friends and I spent some years failing to solve it before finding out it should have been 4. Therefore, I am personally convinced (but cannot prove) that 3 is not possible: Consider a row of clones, say #1, #2, #3, #4, #5...
by Pelli
Fri Jun 26, 2009 6:38 am UTC
Forum: Logic Puzzles
Topic: Yet another hat problem
Replies: 10
Views: 2557

Re: Yet another hat problem

Here is a solution for when gaps are left and sight is 4. The system we wish to set up is that n, n+1 know their colours while n+2 knows the relation between n+1 and n+2, for n incrementing in steps of two. "Given" n, let n,n+1 (who both know their colours and see n+3,n+4) guess co...

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