[Guest]

There is a 5 story lighthouse out on a rock in the ocean. At the top of the lighthouse, there are three lightbulbs attached to the wall. At the base of the lighthouse there are three switches that control them but you don't know which switch corresponds to which light. At the beginning all the lights are off and you are at the base of the lighthouse. Without ripping out the wires from the wall or anything like that, what is the least number of trips you must make up or down the long staircase to figure out which switch controls each of the lights?

[Guest]

if u can start on top u loosen 1 of the bulbs then go down turn 2 random switihes on then walk up and use logic:P

or if u can loosen them you

turn on 1 light switich walk up check walk down turn on a different one and check again

[Guest]

.... only one trip up the stairs to know which light switch controls the light bulb.

You flip on switch #1. Wait five minutes, flip off switch #1.

Flip on switch #2. Run up the stairs.

One of the light bulbs will be on. That is the bulb controlled by switch #2.

One of the light bulbs will be off but warm. That is the bulb controlled by switch #1.

One of the light bulbs will be off and cold. That is the bulb controlled by switch #3.

And now that you have figured out which light switch controls each light, you now get to figure out what the heck you are doing on a rock in the middle of the ocean in the first place.

[Guest]

.... only one trip up the stairs to know which light switch controls the light bulb.

You flip on switch #1. Wait five minutes, flip off switch #1.

Flip on switch #2. Run up the stairs.

One of the light bulbs will be on. That is the bulb controlled by switch #2.

One of the light bulbs will be off but warm. That is the bulb controlled by switch #1.

One of the light bulbs will be off and cold. That is the bulb controlled by switch #3.

And now that you have figured out which light switch controls each light, you now get to figure out what the heck you are doing on a rock in the middle of the ocean in the first place.

a flaw for yorus and mine is what if you cant reach the light bulb i.e 6M up the wall (nothing to climb on)

What if its freezing in the light house?

And now that you have figured out which light switch controls each light, you now get to figure out what the heck you are doing on a rock in the middle of the ocean in the first place.

Correct lol y would u be in a lighthouse in the first place

[Guest]

Answer: 2 up, 1 down

Notation: "=>" means "corresponds to"

How:

step 1 - flip any two switches

step 2 - go UP; off bulb=>unflipped switch

step 3 - go DOWN; unflip one of flipped switches

step 4 - go UP; bulb that turned off=>most recent pulled switch, last bulb=>other flipped switch.

[Guest]

you dont have to go up the stairs at all. turn on a switch and look for the lights reflection on the water.

i think its a good guess anyways.

[Guest]

i think its a good guess anyways.

you dont have to go up the stairs at all. turn on a switch and look for the lights reflection on the water.

but that cant be right if the bulbs are on the wall. ill still stick with my answer though.

[bonanova]

Posted here.

If you didn't write the puzzle, do a search [three +switch +light would have found it]

Locked.