There are three on/off switches on the ground floor of a building. Only one operates a single lightbulb on the third floor. The other two switches are not connected to anything. Put the switches in any on/off order you like. Then go to the third floor to check the bulb. Without leaving the third floor, can you figure out which switch is genuine? You get only one try.
Credits: Martin Gardner
Email your solutions to Zach Marinov/Paris Suksmith/Aarit Bhattacharya
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Zach Marinovhttps://etonstem.com/author/zach

Zach Marinovhttps://etonstem.com/author/zach

Zach Marinovhttps://etonstem.com/author/zach

Zach Marinovhttps://etonstem.com/author/zach
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