Author
Message
gagravarr
Greenhorn
Joined: 09 Apr 2006 Posts: 4
TopGun2 wrote:
I can see the 9*6=54 but I can't get 23*2 I'm stuck with 22 or 25 any hints?
The change is in the middle row. Think about all the ways you can balance 14 with weights at 1 and 2 - you should be able to find one that weighs in at 9 rather than 8
Posted: Sun Apr 09, 2006 12:26 pm
TopGun2
Boot
Joined: 30 Nov 2005 Posts: 30 Location: Cambs, UK
Have spotted the 23 now, d'oh!
Will play with matrices later.
_________________Audere Est Facere
Posted: Sun Apr 09, 2006 12:28 pm
Phill4269
Greenhorn
Joined: 24 Feb 2006 Posts: 7 Location: London
The minimum right had side moement is 98 (2x22 + 6x9). This means that the minimum moment divisible by 5 is 100. This can be achieved uniquely on the right hand side.
On the left hand side I have found at least 3 solutions which give a moment of 20x5=100.
Two have been incorrect the third I will try tomorrow. The problem is that all solutions must add up to 20Kg - so can there be only one correct solution?
If there is an error in the card, there isn't much scope! Maybe the answer processing is wrong.
I have tried getting a hint but got no response. Has anyone managed to get a hint?
Posted: Sun Apr 09, 2006 12:48 pm
gagravarr
Greenhorn
Joined: 09 Apr 2006 Posts: 4
Phill4269 wrote:
On the left hand side I have found at least 3 solutions which give a moment of 20x5=100.
Hmm, I only got 2 different ones, based on putting either 4 or 5 for the bottom left hand weight. Where do I tweak for the 3rd?
Phill4269 wrote:
Two have been incorrect the third I will try tomorrow. The problem is that all solutions must add up to 20Kg - so can there be only one correct solution?
Unless there are some extra rules they're using to judge "lightest possible combination", I think there might be an error
Posted: Sun Apr 09, 2006 1:01 pm
hot flan
Guest
as far as i can figure, it's impossible using magma's excel file the lowest total weight possible is 52kg, and there is definitely more than one solution for this. unless some of the weights can be 0 I can't see how this can work
Posted: Sun Apr 09, 2006 2:12 pm
Magma
Veteran
Joined: 10 Jan 2006 Posts: 119
Well if 0 is possible, then the minimum configuration of the system is 0 for each weight. But that would kinda defeat the whole concept of "Weights" wouldn't it?
Posted: Sun Apr 09, 2006 3:25 pm
Stratman
Veteran
Joined: 03 Feb 2006 Posts: 81 Location: Kettering UK
Getting time to call this a day and head for the pub.
100 each side can be done and i dont see how it could be less.
Hope this doesn't sound dumb, but going back to the way Friedman's puzzles usually work...(Sorry, Austin, had another thought on this)...
http://www.stetson.edu/~efriedma/weight/
Thinking about this, using the weights 1,2,3,4...25 could be considered to be the lightest combination as it is worded. Using any combination of weights could mean the lowest weight would not necessarily have to be 1 and they would not have to be consecutive - so higher combinations would be possible.
If so, it could alternately mean 1,2,3,4,5 for the first weight tree and 1,2,3,4...20 for the second.
But of course the card should make it clear that no two weights can be the same value - and it doesn't. It would not be the first card with a mistake on it.
It is the only thing I can think to explain why our 100/100 balances dont get a solve. It also makes the puzzle much harder and probably more worthy of a purple.
_________________There Ain't Half Been Some Clever Bastards...Ian Dury and the Blockheads (1978)
Posted: Sun Apr 09, 2006 4:33 pm
a11420151425
Boot
Joined: 26 Nov 2005 Posts: 10
program Hiya guys i've just got the card and at first glance it didn't look too bad but upon closer inspection it really was. lol. So what i'm gonna see if i do is write a program that'll work out the lowest possible weights for the 3 "stacks" so that the equation 5a = 2b + 6c is true.
I'll post my findings once its done.
Posted: Sun Apr 09, 2006 5:23 pm
Preon neKaskth
Boot
Joined: 08 Apr 2006 Posts: 16
I think by "lightest possible combination", the card refers to the mass of the weights: the lightest of which i've completed the big tree with is 55.
It ends up with the numbered weights being:
4. 2
5. 2
6. 2
7. 1
8. 3
9. 3
10. 6
11. 2
12. 1
I can't see anyother way to do it. But a nice puzzle, I like it.
Posted: Sun Apr 09, 2006 6:37 pm
Grizy
Veteran
Joined: 19 Nov 2005 Posts: 89 Location: Preston, UK
Preon please read previous threads.
There are at least 2 ways of doing it with 52Kgs.
But we still haven't solved it.
Posted: Sun Apr 09, 2006 6:43 pm
Preon neKaskth
Boot
Joined: 08 Apr 2006 Posts: 16
Aha... whoops... didn't register as I went through it... never mind.
Posted: Sun Apr 09, 2006 6:47 pm
a11420151425
Boot
Joined: 26 Nov 2005 Posts: 10
help ok i'm slightly confused... what is the reading on the scales.... is it 6 or 16?
thanks
Posted: Mon Apr 10, 2006 8:30 am
Stratman
Veteran
Joined: 03 Feb 2006 Posts: 81 Location: Kettering UK
six
_________________There Ain't Half Been Some Clever Bastards...Ian Dury and the Blockheads (1978)
Posted: Mon Apr 10, 2006 8:35 am
a11420151425
Boot
Joined: 26 Nov 2005 Posts: 10
thanks kewl thanks for the help
Posted: Mon Apr 10, 2006 8:36 am
gagravarr
Greenhorn
Joined: 09 Apr 2006 Posts: 4
Card has a problem I've just had an email from Perplex City:
Quote:
Thanks for your email.
We're aware that there is a problem with this card and are working on
correcting it. We'll be uploading any alternate answers / corrections as
soonas possible.
So we'll have to wait a little bit and see
Posted: Mon Apr 10, 2006 8:44 am
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