Saturday, December 2, 2017

logical deduction - The heaviest orange




You have a basket of 9 oranges, 8 of the oranges have the same weight and 1 is heavier than the others. All the oranges looks and feels the same. You have a scale but you are allowed to use it only 2 times. How could you find the heaviest orange?



Answer



Split the nine oranges into



Three piles of three, piles A, B, and C.



Compare the weights of



Piles A and B. If they weigh the same, the heavy orange is in pile C. If either of those two piles are heavier, the heavy orange is in that pile.




Then, compare the weights of



Two of the oranges from the heavier pile. If they're the same, then the third orange is the heaviest. If either of those two are heavier, then that's the heaviest orange.



Note:
There are already several puzzles about very similar weighing problems on Puzzling SE, so don't be too surprised if this question doesn't get a ton of positive feedback or is flagged as a duplicate. Don't take it personally, but in the future remember to look at similar questions to make sure it hasn't been asked before.


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