Finding the light coin
You must identify one lighter counterfeit coin among 1000 using a balance scale, which has three outcomes per weighing (left-heavier, right-heavier, or balanced). What is the minimum number of weighings guaranteed to find it?
Show hints (2)+
- A balance scale gives three outcomes per weighing, not two - so think base 3.
- : .
Answer
Reveal answer →Final answer
7
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Asked at: Timed Mental-Math & Sequences, ETF Market-Making