Programmer Humor

The "right" solution doesn't work. Each light switch can turn the lightbulb on by being up or being down. This means there is 3*2=6 possible cases of which light switch state turns on the light bulb. So we need to make 3 observations to bring it down to one case. An example of the original logic failing is that the light bulb being on could mean either that switch 2 being up turns it on, switch 1 being down turns it on, or switch 3 being down turn it on.

I present an alternative solution. Since the conventional solution says that we can feel its temperature, we know the light bulb is within reach. We can visit the room first, unplug the light bulb, and bring it back to the light switches. Then we can check all 2^3 permutations of light switches to see which one effects the bulb. Of course, it is likely that non affects it after unplugging it, but it could be a wireless light bulb.