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Guest Message by DevFuse

# yet another balance puzzle

7 replies to this topic

### #1 phil1882

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Posted 24 October 2013 - 06:16 PM

i bleive this challange may have been posted before, never the less here goes.

you have 3 wieghing scales, a normal scale that gives the correct result, a reverse scale that gives the oppisite result, and a random scale that gives, well you guessed it, a random result.

you have 4 normal coins and 4 heavy coins. your task however is to simply identify which scale is which with the fewest weighings, and you don't intially know which coins are which either.

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### #2 ThunderCloud

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Posted 24 October 2013 - 06:53 PM

Spoiler for If these are balance scales...

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### #3 jamieg

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Posted 24 October 2013 - 06:55 PM

I don't see how this is possible. Theoretically the random scale has a small possibility of replicating either of the constant scales indefinitely just by random chance. If it randomly gives the correct answer the first ten times, any observation on it will be the same as if it were the truth telling scale; same with if it's a hundred or infinite times.

Spoiler for If I'm correct...

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### #4 dgreening

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Posted 24 October 2013 - 08:40 PM

I think you are both on the right track.

Spoiler for

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### #5 shammaa

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Posted 24 October 2013 - 10:04 PM

will the reverse scare read correctly if they are equal?

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### #6 phil1882

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Posted 24 October 2013 - 10:39 PM

yes. the random scale may or may not. i tend to agree. could ptontially be infinite wieghings.

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### #7 bonanova

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Posted 25 October 2013 - 03:25 PM

To make it solvable, change the random scale into an alternating scale.

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Vidi vici veni.

### #8 jamieg

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Posted 27 October 2013 - 05:46 AM

To make it solvable, change the random scale into an alternating scale.

Spoiler for In that case...

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