# Unstable module problem



## danmpem

There is an old computer terminal that is in delicate operation. There are six core modules (labeled A-F), and one is dangerously unstable and needs to be replaced. The computer programmers have run a diagnostic report with each module to indicate which other modules are fully operational. Four of the diagnostic reports have a single error in them. Two are completely accurate.

The unstable module’s diagnostic report is in one of the two that produces accurate results.

The reports are:

A: f e b..........B: d c e...........C: e b a...........D: f a c.............E: f d c..............F: a c d

Which module do they replace?


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## Semper Fidelis

They don't replace the module. They're Appple devotees and decide that all computer problems are due to the fact that Apple did not make the product. They trash the computer and buy an iMac.


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## PuritanCovenanter

A and C


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## Semper Fidelis

A: feb = 111111101011
B: dce = 110111001110
C: eba = 111010111010
D: fac = 111110101100
E: fdc = 111111011100
F: acd = 101011001101


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## Timothy William

C needs to be replaced.

The only error a diagnostic report can give is to falsely state that a module is operational. 4 errors means the unstable module must be given a false indication of fully operational 4 times. Only C is indicated 4 times.


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## danmpem

PuritanCovenanter said:


> A and C



A _and _C?


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## PuritanCovenanter

I am ignorant.


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## danmpem

GAH!!! I just realized why my answer is wrong.

I got this problem while playing Star Wars Knights of the Old Republic II: The Sith Lords (cool name!). Just before Christmas I spent 3 1/2 hours working on the proof as to why the answer was the way it was....and now I know I was wrong. Oh yeah, and when I went back to the game to enter the answer, the game changed it's mind and gave me a different question, so I never really found out the answer until this evening.


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## Timothy William

And the answer is...?


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## danmpem

I completely forgot about this thread. Timothy William is right.


> C needs to be replaced.
> 
> The only error a diagnostic report can give is to falsely state that a module is operational. 4 errors means the unstable module must be given a false indication of fully operational 4 times. Only C is indicated 4 times.



I had a three page proof as to why A needed to be replaced...but I was very, very mistaken.


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