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Attic Lamp Switch

A downstairs panel contains three on-off switches. One of them controls the lamp in your attic. Using only ONE trip up to the attic, how do you determine which switch controls the lamp?

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Discussion

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hugh 5 months ago contains spoiler (show)
emtucifor 6 months ago contains spoiler (show)
santol 6 months ago contains spoiler (show)
electroduction 7 months ago

I like it!

acce245 8 months ago

If you can’t actually see the light to begin with, an incandescent would be hot by the time you got their anyway. Although, sgarre1 makes a good point too.

bmcmillantx 10 months ago

What if the light is a compact fluorescent?

gluec 10 months ago contains spoiler (show)
sgarre1 10 months ago contains spoiler (show)
thefairytale 10 months ago

When a light is on it gets hot, so if you turn the first switch on and wait a while then turn the second one on and go to the attic you can tell if it was the first one by the heat of the lamp since the light would have made it hot, it would have been cold if it was the second, last turned on switch that gave the light power. Also, the question says to find the answer in ONE trip, your method involved 3 at the most.

jay_santos about 1 year ago contains spoiler (show)
valentin about 1 year ago

Haha, that is quite clever.