Feeding Crows
Gold Member
- Jun 12, 2021
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You have 12 cue balls that look exactly the same. 11 of them weigh exactly the same, and the 12th is slightly lighter or heavier, but so slightly that you cannot tell without a scale.
You have a legal scale and you get 3 chances to weigh the cue balls against each other.
After the 3rd weighing, you must be able to determine which cue ball is different, and whether it is lighter or heavier than the others. This process must be the same every time, and work every time in every possible scenario. No getting lucky!
It took me one week, about an hour a day to figure it out in my head. My daughter brought me math equations and did it in two days. Though how long she took in those two days could have rivaled my hour-a-day. Still! She did it with math. I did it with logic in my head. So there's two ways to figure out this puzzle, and they're both the same answer.
Let's see who's smart.
You have a legal scale and you get 3 chances to weigh the cue balls against each other.
After the 3rd weighing, you must be able to determine which cue ball is different, and whether it is lighter or heavier than the others. This process must be the same every time, and work every time in every possible scenario. No getting lucky!
It took me one week, about an hour a day to figure it out in my head. My daughter brought me math equations and did it in two days. Though how long she took in those two days could have rivaled my hour-a-day. Still! She did it with math. I did it with logic in my head. So there's two ways to figure out this puzzle, and they're both the same answer.
Let's see who's smart.