Finding the Heavier Doobie: Determining the Hash-filled One in 2 Weighs

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Discussion Overview

The discussion revolves around a problem involving nine doobies, one of which is heavier due to containing hash. Participants are tasked with determining which doobie is heavier using a balance beam scale in only two weighs. The scope includes problem-solving and mathematical reasoning.

Discussion Character

  • Exploratory, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant outlines a method involving weighing groups of doobies to identify the heavier one, but the clarity of the approach is questioned.
  • Another participant references a previous solution related to weights, suggesting a connection to the current problem, though the relevance is unclear.
  • A participant expresses frustration with mathematical concepts, indicating a struggle with the problem but believes their proposed solution is correct under certain conditions.

Areas of Agreement / Disagreement

There appears to be no consensus on the proposed methods for solving the problem, with multiple competing approaches and some participants expressing uncertainty about their own contributions.

Contextual Notes

Some assumptions about the weighing process and the definitions of "heaviest" may not be fully articulated, leading to potential misunderstandings in the proposed solutions.

Who May Find This Useful

Individuals interested in mathematical problem-solving, logic puzzles, or those exploring combinatorial reasoning may find this discussion relevant.

Tau_Muon_PlanetEater
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There are nine doobies on a table of equal size but one of them contains hash which makes it weigh more than the other eight doobies. You have a balance beam scale in front of you that you can use weigh the doobies only twice. Determine the method of finding out which doobie contains the hash, using only two weighs.
 
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Weigh 123x456 .
If 123 is the heaviest, then weigh 1x2 . If 1 equals 2 , pick 3 ; if not, pick the heaviest.
If 123 is the lightest, then weigh 4x5 . If 4 equals 5 , pick 6 ; if not, pick the heaviest.
If 123 equals 456 , then weigh 7x8 . If 7 equals 8 , pick 9 ; if not, pick the heaviest.

________________

I hope you have understood the Forty 1lb Weights' solution...
 
Last edited:
BTW, take a look at the threads 'Nine Digit Numbers' and
'I lost my calculator batteries in a flood' , too.

I guess you've lost your calculator batteries... :smile:
 
Last edited:
Roger that Rogerio. Sorry I am not a math guy. I try and try but ultimately I am stupid. The doctor forgot to catch me when I popped our of my mother and I landed head first. P.S. My lb. weight solution is correct I think, if you can only put weights on one scale end.
 

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