CJ Posted February 14, 2008 Share Posted February 14, 2008 If you have seen this on the int'net, please refrain from spoiling. Your job is to measure 45 minutes, if you have only two igniter cords and matches to light the cords. The two igniter cords have the following features: 1. They are twisted from various materials and also different parts can burn at different speed (e. g. after ten minutes they will not burn at the same point). 2. Every cord burns from ignition to the end exactly one hour. Describe your way of measuring the 45 minutes. Link to comment Share on other sites More sharing options...
AndrewOW Posted February 14, 2008 Share Posted February 14, 2008 I'd just look at my watch. (I have no idea ) Link to comment Share on other sites More sharing options...
Digsy Posted February 14, 2008 Share Posted February 14, 2008 How about: Bend one chord into a circle so that the ends meet. Next, lay the second chord so that one of its ends touches the joined ends if the circular chord (to form a "lollipop" shape). Light all three the toucing ends simultaneously. The circular chord will burn from both ends until both flames meet in exactly half an hour, at which point the straight chord will also have a half hour left to burn. When the circular chord burns out, light the other end of the straight chord. The straight chord will then burn out in 15 minutes. Total time = 30 mins for the circular chord plus 15 mins for the straight one: 45 mins. Link to comment Share on other sites More sharing options...
Havard Posted February 14, 2008 Share Posted February 14, 2008 I'd just look at my watch. (I have no idea ) I have had a look at the answer to this and to be honest I am not convinced...... I feel that the fact that the insides of the cables burn at different speeds at times, makes it impossible to be accurate, waits for someone who is clever to correct me! H. Link to comment Share on other sites More sharing options...
marc_p Posted February 14, 2008 Share Posted February 14, 2008 How about: Bend one chord into a circle so that the ends meet. Next, lay the second chord so that one of its ends touches the joined ends if the circular chord (to form a "lollipop" shape). Light all three the toucing ends simultaneously. The circular chord will burn from both ends until both flames meet in exactly half an hour, at which point the straight chord will also have a half hour left to burn. When the circular chord burns out, light the other end of the straight chord. The straight chord will then burn out in 15 minutes. Total time = 30 mins for the circular chord plus 15 mins for the straight one: 45 mins. Smart arse, but definetly right, well done. Link to comment Share on other sites More sharing options...
MrRalphMan Posted February 14, 2008 Share Posted February 14, 2008 I have had a look at the answer to this and to be honest I am not convinced...... I feel that the fact that the insides of the cables burn at different speeds at times, makes it impossible to be accurate, waits for someone who is clever to correct me! H. Doesn't matter if different parts burn at different speeds, the overall time is always 60 mins.. The circle will burn in 30mins as if one way only burns 10 deg in 30 mins the otherway must burn 350 deg.. Same with the straight one. I didn't get it, but kudos to Digsy though... Link to comment Share on other sites More sharing options...
CJ Posted February 14, 2008 Author Share Posted February 14, 2008 I will leave it run until this evening and then post up what the answer was on the site. It is different to Digsy's answer (though I am not saying that is incorrect). Link to comment Share on other sites More sharing options...
Matt H Posted February 14, 2008 Share Posted February 14, 2008 I'm going to say its something to do with burning one to the point that its half way through, then thats 30 mins and then measureing the difference or something, i'm going to have a think! Link to comment Share on other sites More sharing options...
Sheefa Posted February 14, 2008 Share Posted February 14, 2008 Count 45 minutes in my head. People always look for the most complex, brain numbing solutions. Link to comment Share on other sites More sharing options...
CJ Posted February 14, 2008 Author Share Posted February 14, 2008 Count 45 minutes in my head. People always look for the most complex, brain numbing solutions. Not the most accurate way though eh? Link to comment Share on other sites More sharing options...
Scoboblio Posted February 14, 2008 Share Posted February 14, 2008 Stuff Now that's some first class methodical thinking! Link to comment Share on other sites More sharing options...
Havard Posted February 14, 2008 Share Posted February 14, 2008 Doesn't matter if different parts burn at different speeds, the overall time is always 60 mins.. The circle will burn in 30mins as if one way only burns 10 deg in 30 mins the otherway must burn 350 deg.. Same with the straight one. I didn't get it, but kudos to Digsy though... I stand corrected. Forget the first cable as that is easy. The second cable will burn for half an hour with the first so there must be half an hour left. you then set fire to the other end, when they meet it has to be 15 mins...... H. Link to comment Share on other sites More sharing options...
Matt H Posted February 14, 2008 Share Posted February 14, 2008 I stand corrected. Forget the first cable as that is easy. The second cable will burn for half an hour with the first so there must be half an hour left. you then set fire to the other end, when they meet it has to be 15 mins...... H. have you worked out that plane on a tread mill yet H? Link to comment Share on other sites More sharing options...
Havard Posted February 14, 2008 Share Posted February 14, 2008 have you worked out that plane on a tread mill yet H? Yeah mate! Re-read the thread, with the engines running it will obviously take off..... H. Link to comment Share on other sites More sharing options...
Matt H Posted February 14, 2008 Share Posted February 14, 2008 Yeah mate! Re-read the thread, with the engines running it will obviously take off..... H. obviously Link to comment Share on other sites More sharing options...
Havard Posted February 14, 2008 Share Posted February 14, 2008 obviously I thought it was a joke at first. I got it in my head that someone was asking if a plane would take off if you ran the wheels fast enough, without the engines!! H. Link to comment Share on other sites More sharing options...
CJ Posted February 14, 2008 Author Share Posted February 14, 2008 This was the solution given: Igniter Cords - solution Start fire on both ends of one igniter cord and on one end of the second igniter cord. The very moment the first cord (where both ends burn) stops burning (that is after 30 minutes), start fire on the other end of the second cord (otherwise it would burn another 30 minutes). Thus the second igniter cord burns just 15 minutes from then. And that is all together 45 minutes. Link to comment Share on other sites More sharing options...
RiceRocket Posted February 14, 2008 Share Posted February 14, 2008 1. They are twisted from various materials and also different parts can burn at different speed (e. g. after ten minutes they will not burn at the same point). So the two igniter cords are identical...? Link to comment Share on other sites More sharing options...
chilli Posted February 14, 2008 Share Posted February 14, 2008 that's really cool mine started the same, burn both ends of the 1st cord for 30mins but then I'd bend the second so it's doubled up then doubled up again then when the first burns out I'd light both ends of the second cord + at both bends where it's doubled back, giving 4 burns and a burn time of 15mins - 30 + 15 = 45 think it would work but it's not as neat as the actual solution given, that's nifty- I should have thought of that! Link to comment Share on other sites More sharing options...
Digsy Posted February 14, 2008 Share Posted February 14, 2008 I've been off work all week with the flu. This is the first interesting thing I've had to do Link to comment Share on other sites More sharing options...
SUPRASUZUKI Posted February 14, 2008 Share Posted February 14, 2008 I've been off work all week with the flu. This is the first interesting thing I've had to do This is the most interesting thing you've ever done! (only joking mate.....) Link to comment Share on other sites More sharing options...
CJ Posted February 14, 2008 Author Share Posted February 14, 2008 I've been off work all week with the flu. This is the first interesting thing I've had to do Would you like another tomorrow? Link to comment Share on other sites More sharing options...
Digsy Posted February 14, 2008 Share Posted February 14, 2008 Oh, go on then, but I may just have a lie in tomorrow Link to comment Share on other sites More sharing options...
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