New Logic/Math Puzzles Latest Questionshttp://brainden.com/forum/forum/7-new-logicmath-puzzles/New Logic/Math Puzzles Latest QuestionsenBraindencom-NewPuzzleshttps://feedburner.google.comSubscribe with My Yahoo!Subscribe with NewsGatorSubscribe with My AOLSubscribe with BloglinesSubscribe with NetvibesSubscribe with GoogleSubscribe with PageflakesWho can go the lowest?http://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/r1PTnxdsyWU/<p>
A game token costs $10 to play. The pay out is $100. You can purchase multiple entries if you desire. For each entry you purchase, you must pick the lowest positive number that no one else picks. If there are ten people, including yourself, seeking to purchase tokens, what is your strategy?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/r1PTnxdsyWU" height="1" width="1" alt=""/>18031Thu, 19 Oct 2017 14:43:14 +0000http://brainden.com/forum/topic/18031-who-can-go-the-lowest/Raven's Progressive Matriceshttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/NJY51ojy-8o/<p style="background-color:#ffffff;color:#353c41;font-size:14px;">
Hello, I did couple online IQ tests with Raven's matrices and there are some matrices where i can't figure out logic beside them and they are driving me crazy. <br />
Tests have 3 x 3 matrix and there is some logic sequence, which you have to figure out and choose the missing piece from six samples that are given to you.
</p>
<p style="background-color:#ffffff;color:#353c41;font-size:14px;">
Do you have any idea?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/NJY51ojy-8o" height="1" width="1" alt=""/>18029Sat, 14 Oct 2017 03:22:06 +0000http://brainden.com/forum/topic/18029-ravens-progressive-matrices/Help!http://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/b_fVu9btWdY/<p>
Friend gave me this puzzle. Told me not to overthink it. Im so stuck!
</p>
<p><a href="http://brainden.com/forum/uploads/monthly_2017_10/Screenshot_20171015-200025.jpg.62af715052999ba70ad3a363cf54c30b.jpg" class="ipsAttachLink ipsAttachLink_image"><img data-fileid="4496" src="http://brainden.com/forum/uploads/monthly_2017_10/Screenshot_20171015-200025.jpg.62af715052999ba70ad3a363cf54c30b.jpg" class="ipsImage ipsImage_thumbnailed" alt="Screenshot_20171015-200025.jpg"></a></p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/b_fVu9btWdY" height="1" width="1" alt=""/>18030Sun, 15 Oct 2017 09:13:08 +0000http://brainden.com/forum/topic/18030-help/Segment a segmenthttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/_RBbz0tDDis/<p>
In front of you is a line and a line segment. You need to dissect the line segment into 6 equal segments. Unfortunately you only possess two skills. you have the ability to mark points and you have the ability to draw straight segments. How will you segment the segment into six equal parts?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/_RBbz0tDDis" height="1" width="1" alt=""/>18023Fri, 06 Oct 2017 00:19:52 +0000http://brainden.com/forum/topic/18023-segment-a-segment/Determining an ellipse given a focihttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/b_2WRnPWd5w/<p>
How many points would you need to have to uniquely determine an ellipse given that you know a foci is located at (0,0).
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/b_2WRnPWd5w" height="1" width="1" alt=""/>18013Mon, 11 Sep 2017 14:20:32 +0000http://brainden.com/forum/topic/18013-determining-an-ellipse-given-a-foci/Chess Board Puzzlehttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/guoiTC1VC_s/<p>
Use the twelve pieces on the left to create a chess board, The pieces may be flipped!
</p>
<p><a href="http://brainden.com/forum/uploads/monthly_2017_05/59158d3b01b35_CBPuzzle.jpg.3d185ebbd865192549753324c2631e97.jpg" class="ipsAttachLink ipsAttachLink_image"><img data-fileid="4474" src="http://brainden.com/forum/uploads/monthly_2017_05/59158d3b52c90_CBPuzzle.thumb.jpg.d36e7694a315d28341dc0e1fa71fbe45.jpg" class="ipsImage ipsImage_thumbnailed" alt="CB Puzzle.jpg"></a></p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/guoiTC1VC_s" height="1" width="1" alt=""/>17947Fri, 12 May 2017 10:25:54 +0000http://brainden.com/forum/topic/17947-chess-board-puzzle/Proof that there exist only one answerhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/bumpBgFKTis/<p>
Prove that x^(1/x) = x^-x has only one solution
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/bumpBgFKTis" height="1" width="1" alt=""/>18027Tue, 10 Oct 2017 18:37:35 +0000http://brainden.com/forum/topic/18027-proof-that-there-exist-only-one-answer/Russian Roulettehttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/iG4422cDOak/<p>
You and four friends are playing Russian roulette, one bullet is in a chamber of a six chamber gun. Each of you must take a shot from the gun. The chamber will only be spun once, before anyone has taken a shot. If you got to chose, which position, 1st, 2nd, 3rd, 4th, or 5th would best help your chances of survival?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/iG4422cDOak" height="1" width="1" alt=""/>18024Mon, 09 Oct 2017 16:42:48 +0000http://brainden.com/forum/topic/18024-russian-roulette/A rational solutionhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/spbQIuWMEcU/<p>
For 0<x<y find an integer solution for
</p>
<p>
x^y = y^x
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/spbQIuWMEcU" height="1" width="1" alt=""/>18021Thu, 05 Oct 2017 14:20:42 +0000http://brainden.com/forum/topic/18021-a-rational-solution/Persistencehttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/P7312RuJqaE/<p>
A number's persistence is the number of steps required to reduce it to a single digit by multiplying all its digits to obtain a second number, then multiplying all the digits of that number to obtain a third number, and so on until a one-digit number is obtained. For example, 77 has a persistence of four because it requires four steps to reduce it to one digit: 77-49-36-18-8. The smallest number of persistence one is 10, the smallest of persistence two is 25, the smallest of persistence three is 39, and the smaller of persistence four is 77. What is the smallest number of persistence five?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/P7312RuJqaE" height="1" width="1" alt=""/>18020Thu, 05 Oct 2017 14:16:07 +0000http://brainden.com/forum/topic/18020-persistence/Month Codeshttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/gXsCmCuSmJ0/<p>
Here is a list of months and a code for each
</p>
<p>
January: 7110<br />
February: 826<br />
March: 5313<br />
April: 541<br />
May: 3513<br />
June: 4610<br />
July: 4710
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<p>
<br />
What is the code for the month of August?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/gXsCmCuSmJ0" height="1" width="1" alt=""/>18022Thu, 05 Oct 2017 14:24:00 +0000http://brainden.com/forum/topic/18022-month-codes/<link>http://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/iuWV2KXRuaM/</link><description><p>this is a riddle that has been in my family for, according to my great grandma, 6 generations. unless you guess correctly, you aren't told until you reach the age of 21. I guessed it correctly at 14, can you?</p><p>
</p><p>
"Way down in a deep, dark, dungeon; all saddled, all bridled, alll ready to fight. I silks my bow, I hairs my fiddle, I told you my name three times in this riddle."</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/iuWV2KXRuaM" height="1" width="1" alt=""/></description><guid isPermaLink="false">7903</guid><pubDate>Sun, 26 Apr 2009 16:00:51 +0000</pubDate><feedburner:origLink>http://brainden.com/forum/topic/7903--/</feedburner:origLink></item><item><title>Superman vs a black holehttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/Wpa1PCq8L9M/<p>
Suppose superman can survive the vacuum of space (the comics are inconsistent with this ability). Let's say he is in the front of a spaceship that just crossed, what I believe in English is called, the event horizon for a black hole. That point where matter gets sucked into hole. Is it possible for superman to move to the rear of the ship and escape the black hole, assuming that the back of the ship hasn't crossed the event horizon?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/Wpa1PCq8L9M" height="1" width="1" alt=""/>18019Wed, 04 Oct 2017 05:10:08 +0000http://brainden.com/forum/topic/18019-superman-vs-a-black-hole/Finding a functionhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/lZnoz8Jdtmg/<p>
Find a continuous function where the following identity is true: f(2x) = 3f(x)
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/lZnoz8Jdtmg" height="1" width="1" alt=""/>18015Fri, 22 Sep 2017 20:04:28 +0000http://brainden.com/forum/topic/18015-finding-a-function/Protecting Airplaneshttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/x2jQCc2LYk4/<p style="background-color:#ffffff;color:#222222;font-size:19px;">
Abraham is tasked with reviewing damaged planes coming back from sorties over Germany in the Second World War. He has to review the damage of the planes to see which areas must be protected even more.
</p>
<p style="background-color:#ffffff;color:#222222;font-size:19px;">
Abraham finds that the fuselage and fuel system of returned planes are much more likely to be damaged by bullets or flak than the engines. What should he recommend to his superiors?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/x2jQCc2LYk4" height="1" width="1" alt=""/>18011Fri, 08 Sep 2017 12:22:34 +0000http://brainden.com/forum/topic/18011-protecting-airplanes/A gambling problemhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/GMJTUZ1ipeU/<p>
A gambler has $5,000 and is playing a game of chance with a win probability of .95. Every time he wins, he raises his stake to 1/4, of his bankroll. The gambler doesn't reduce his stake when he loses
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<p>
If he keeps at it, what are his expected winnings?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/GMJTUZ1ipeU" height="1" width="1" alt=""/>18010Fri, 08 Sep 2017 12:21:16 +0000http://brainden.com/forum/topic/18010-a-gambling-problem/City Growthhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/qAD-vYsMVNA/<p>
A town's population of size x doubled after 30 years (2x). How long ago was this population 1/2x?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/qAD-vYsMVNA" height="1" width="1" alt=""/>18009Fri, 08 Sep 2017 12:12:22 +0000http://brainden.com/forum/topic/18009-city-growth/Coloring a gridhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/XCf8dF6Lcc4/<p>
You are to color a 5x5 square grid using green, red, blue, and yellow. You must color it in a way where a square cannot share a side or a vertex with another square of the same color. <strong>What is the fewest amount of yellow squares needed to color this appropriately</strong>?
</p>
<p>
</p>
<p>
Now instead lets divide each square diagonally from the top left corner to the bottom right corner. What is the fewest amount of yellow colorings needed?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/XCf8dF6Lcc4" height="1" width="1" alt=""/>18003Mon, 21 Aug 2017 13:02:04 +0000http://brainden.com/forum/topic/18003-coloring-a-grid/A circle between three circleshttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/B_ReRx1agxk/<p>
Let's say that there are three congruent circles that are tangent to each other. Draw a fourth congruent circle with its center at the center of the gap formed between the three circles. If all four circles are unit circles, what is the area of the overlap?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/B_ReRx1agxk" height="1" width="1" alt=""/>17996Thu, 10 Aug 2017 16:09:42 +0000http://brainden.com/forum/topic/17996-a-circle-between-three-circles/Connect Fourhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/_dnDDcxycc8/<p>
The classic board game Connect Four has a winning strategy for the first player.
</p>
<p>
The traditional dimensions of the board is 7 wide by 6 tall.
</p>
<p>
For which dimensions does the first player have a winning strategy?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/_dnDDcxycc8" height="1" width="1" alt=""/>18008Thu, 07 Sep 2017 14:23:51 +0000http://brainden.com/forum/topic/18008-connect-four/Connect Fourhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/oam7PyiUU9Y/<p>
The classic board game Connect Four has a winning strategy for the first player.
</p>
<p>
The traditional dimensions of the board is 7 wide by 6 tall.
</p>
<p>
For which dimensions does the first player have a winning strategy?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/oam7PyiUU9Y" height="1" width="1" alt=""/>18007Wed, 06 Sep 2017 12:51:42 +0000http://brainden.com/forum/topic/18007-connect-four/Balancing Gold Coinshttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/FZUNjbg8XQc/<p>
A reversal of a classic problem.
</p>
<p>
You have a bag of gold coins. They are all of the exact same weight except one, which is a fake.
</p>
<p>
You have a balance scale, which you can only use N times. What is the maximum number of coins from which you can pick out the fake?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/FZUNjbg8XQc" height="1" width="1" alt=""/>17991Thu, 10 Aug 2017 13:18:30 +0000http://brainden.com/forum/topic/17991-balancing-gold-coins/New "paper puzzle" game - interested in design feedback!http://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/HrlQkN96kjU/<p>
Hello everyone! My name's Mark Johnson, and alongside Professor Simon Colton (<a href="http://ccg.doc.gold.ac.uk/simoncolton/" rel="external nofollow">http://ccg.doc.gold.ac.uk/simoncolton/</a>) of the Computational Creativity Group (<a href="http://ccg.doc.gold.ac.uk/" rel="external nofollow">http://ccg.doc.gold.ac.uk/</a>) at Goldsmiths College and an artificial intelligence known as the HR system (<a href="http://www.doc.ic.ac.uk/~sgc/hr/" rel="external nofollow">http://www.doc.ic.ac.uk/~sgc/hr/</a>), we've been developing a new kind of paper puzzle game. We're calling it Donatsu!
</p>
<p>
The HR system is a piece of software that automatically creates mathematical concepts and discovers conjectures about them. The system is now capable of generating and testing the solvability of puzzles within wide constraints, and we’ve developed a set of puzzles we’re calling Donatsu (transliterated Japanese for “Doughnut”). These involve the player following a loop (or various other loop-like designs) attempting to get a series of numbers to reach particular totals through adding mathematical operators (+, -, /, and x).
</p>
<p>
I've pasted in below four of the many permutations we've developed - Uninatsu (the most basic), Chromanatsu, Maxinatsu, and Hexanatsu (the most complex) - alongside appropriate instructions. You can also download to print off a paper version, since these are paper puzzles, after all! Our long-term goal is to develop and refine these to the point that we can potentially get some published in newspapers.
</p>
<p>
Seeing as these are designed to be done with pen and paper, you can download a PDF of all the puzzles here: <a href="http://www.ultimaratioregum.co.uk/game/download/donatsu-v1/?wpdmdl=6391" rel="external nofollow">http://www.ultimaratioregum.co.uk/game/download/donatsu-v1/?wpdmdl=6391</a>
</p>
<p>
So: we'd love to get your feedback! Aside from the obvious - are these fun and interesting to solve - we'd also like to ask two main questions: 1) which did you like most, and why, and 2) what would you improve about the puzzles? This is still the early stage of development, so we're trying to pin down the best puzzle permutations possible. Thanks!
</p>
<p>
<img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don0.png" class="ipsImage" alt="Don0.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don1.png" class="ipsImage" alt="Don1.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don2.png" class="ipsImage" alt="Don2.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don3.png" class="ipsImage" alt="Don3.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don4.png" class="ipsImage" alt="Don4.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don5.png" class="ipsImage" alt="Don5.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don6.png" class="ipsImage" alt="Don6.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don7.png" class="ipsImage" alt="Don7.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don8.png" class="ipsImage" alt="Don8.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don9.png" class="ipsImage" alt="Don9.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don10.png" class="ipsImage" alt="Don10.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don11.png" class="ipsImage" alt="Don11.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don12.png" class="ipsImage" alt="Don12.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don13.png" class="ipsImage" alt="Don13.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don14.png" class="ipsImage" alt="Don14.png" /><br /><img src="http://www.ultimaratioregum.co.uk/perhaps/wp-content/uploads/2017/09/Don15.png" class="ipsImage" alt="Don15.png" /></p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/HrlQkN96kjU" height="1" width="1" alt=""/>18006Sun, 03 Sep 2017 01:44:43 +0000http://brainden.com/forum/topic/18006-new-paper-puzzle-game-interested-in-design-feedback/Probability of selecting two blue discs back to backhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/9u0mTqATnNY/<p style="color:#000000;font-size:15.84px;">
If a box contains twenty-one coloured discs, composed of fifteen blue discs and six red discs, and two discs were taken at random, it can be seen that the probability of taking two blue discs, P(BB) = (15/21)×(14/20) = 1/2.
</p>
<p style="color:#000000;font-size:15.84px;">
The next such arrangement, for which there is exactly 50% chance of taking two blue discs at random, is a box containing eighty-five blue discs and thirty-five red discs.
</p>
<p style="color:#000000;font-size:15.84px;">
By finding the first arrangement to contain over 10<sup>12</sup><span> </span>= 1,000,000,000,000 discs in total, determine the number of blue discs that the box would contain.
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/9u0mTqATnNY" height="1" width="1" alt=""/>18002Mon, 21 Aug 2017 12:50:20 +0000http://brainden.com/forum/topic/18002-probability-of-selecting-two-blue-discs-back-to-back/Two people cross a riverhttp://feedproxy.google.com/~r/Braindencom-NewPuzzles/~3/d0E3fEgPDJs/<p>
Answers in spoilers, please.
</p>
<p>
Two people wish to cross a river. There is only one boat. The boat can only carry one person at a time. A person can not cross the river unless in the boat. The boat can not cross the river without someone in it. Both people cross the river. Can you explain how it happened?
</p><img src="http://feeds.feedburner.com/~r/Braindencom-NewPuzzles/~4/d0E3fEgPDJs" height="1" width="1" alt=""/>18001Thu, 17 Aug 2017 05:02:35 +0000http://brainden.com/forum/topic/18001-two-people-cross-a-river/