# Commom Sense Puzzle

likeforest
Posers and Puzzles 22 Oct '06 20:14
1. 22 Oct '06 20:14
You are in the basement of a three story house. There are three floors above you, each containing one light operated by three switches in the basement. Your task is to label each switch corresponding to the floor it operates. You are allowed to go upstairs only once, visiting each floor only once. You cannot see any lights from the basement.
2. 22 Oct '06 20:33
presumably the switches are relative to floors, ie the furthest left one operates either the top floor or tghe immediately higher floor, and the furthest right switch will be the other, therefore the middle one always switches on and off the middle floor of the three higher floors. therefore switch either the furthest left switch on, or the furthest right one and walk up the stairs, see which one that is, label it, label the middle as the middle which we already know it is, and the remaining switch as trhe remaining floor
3. 22 Oct '06 20:37
No sorry, thats not the solution. Why do you asume that the middle switch operates the middle floor? The middle switch may operate any one of the floors.
4. 22 Oct '06 22:34
Assuming you know they are all off originally, turn one switch on, leave one switch off. The third switch turn on for a minute or so and turn off again.

When you go upstairs, one light will be on & two off. One of the off ones should be warm to the touch, having been on for a while (assuming standard bulbs). Therefore, you should be able to label the switches correctly.
5. 22 Oct '06 22:371 edit
Coulnt be easier. Bravo!
6. 26 Oct '06 21:32
Originally posted by kody magic
Assuming you know they are all off originally, turn one switch on, leave one switch off. The third switch turn on for a minute or so and turn off again.

When you go upstairs, one light will be on & two off. One of the off ones should be warm to the touch, having been on for a while (assuming standard bulbs). Therefore, you should be able to label the switches correctly.
i love it
7. 29 Oct '06 01:57
Originally posted by kody magic
Assuming you know they are all off originally, turn one switch on, leave one switch off. The third switch turn on for a minute or so and turn off again.

When you go upstairs, one light will be on & two off. One of the off ones should be warm to the touch, having been on for a while (assuming standard bulbs). Therefore, you should be able to label the switches correctly.
You wouldn't be able to label the switches. Because although you deduced which switch is for which light, you are only allowed to visit each floor once, and once you had travelled to the third floor, you would not be able to go back down. If you decided to jump out the window, you would still need to re-enter the house and that would be at a floor you've already been to (including the basement).

Someone else could label the switches if you yelled really loud. But in that case, I would instead yell for help in getting down. Maybe a firefighter would have to come to the rescue and you could explain your folly in even attempting this lame puzzle.
8. 29 Oct '06 06:39
Originally posted by Gastel
You wouldn't be able to label the switches. Because although you deduced which switch is for which light, you are only allowed to visit each floor once, and once you had travelled to the third floor, you would not be able to go back down. If you decided to jump out the window, you would still need to re-enter the house and that would be at a floor you've al ...[text shortened]... ve to come to the rescue and you could explain your folly in even attempting this lame puzzle.
The condition states clearly: "You are allowed to go upstairs only once" and a sub condition while going upstairs: "visiting each floor only once."
It doesn't give any conditions at all while going downstairs.

So while climbing upwards you can't visiting a floor more than once. But it says nothing how you'd do while going downstairs. Right?

So you can, in fact, visit each floor (but the top one) more than once.

The problm is consistent and the answer is consistent.
A very good problem with a very good answer.
9. Natural Science
blunderer of pawns
29 Oct '06 10:47
Originally posted by FabianFnas
The condition states clearly: "You are allowed to go upstairs only once" and a sub condition while going upstairs: "visiting each floor only once."
It doesn't give any conditions at all while going downstairs.

So while climbing upwards you can't visiting a floor more than once. But it says nothing how you'd do while going downstairs. Right?

So you ...[text shortened]... is consistent and the answer is consistent.
A very good problem with a very good answer.
You could actually eliminate all of that confusion about going upstairs and visiting each floor once, simply by having all the lights in the same room and stipulating that you can only visit that room once.
10. 29 Oct '06 14:26
Originally posted by Natural Science
You could actually eliminate all of that confusion about going upstairs and visiting each floor once, simply by having all the lights in the same room and stipulating that you can only visit that room once.
But then it is not the original problem, is it?
11. Natural Science
blunderer of pawns
29 Oct '06 14:32
Originally posted by FabianFnas
But then it is not the original problem, is it?
It's the original problem as I know it. I've never seen this problem incorporate seperate floors for the lights. And who would design a light circuit such as 3 switches in the same location, control 3 lights in completely different areas in the house?
12. 29 Oct '06 16:40
Originally posted by Natural Science
It's the original problem as I know it. I've never seen this problem incorporate seperate floors for the lights. And who would design a light circuit such as 3 switches in the same location, control 3 lights in completely different areas in the house?
The problem initially proposed by the creator of this thread is:
"You are in the basement of a three story house. There are three floors above you, each containing one light operated by three switches in the basement. Your task is to label each switch corresponding to the floor it operates. You are allowed to go upstairs only once, visiting each floor only once. You cannot see any lights from the basement."

"You could actually eliminate all of that confusion about going upstairs and visiting each floor once, simply by having all the lights in the same room and stipulating that you can only visit that room once."

We are appearantly not talking about the same problem...
13. Natural Science
blunderer of pawns
29 Oct '06 20:59
Originally posted by FabianFnas
The problem initially proposed by the creator of this thread is:
"You are in the basement of a three story house. There are three floors above you, each containing one light operated by three switches in the basement. Your task is to label each switch corresponding to the floor it operates. You are allowed to go upstairs only once, visiting each floor on ...[text shortened]... can only visit that room once."

We are appearantly not talking about the same problem...
I know what the original problem is, as stated by the original poster. But this problem existed before the original poster posted it. In the version that I know, all of the lights are in one room, and you can go into that room only once. The advantage of telling it this way, instead of having the three lights on three seperate floors, is that you avoid any confusion that might stem from the "visit each floor only once" mandate. The disadvantage is....well, actually there is no disadvantage.
14. 29 Oct '06 21:32
Originally posted by Natural Science
I know what the original problem is, as stated by the original poster. But this problem existed before the original poster posted it. In the version that I know, all of the lights are in one room, and you can go into that room only once. The advantage of telling it this way, instead of having the three lights on three seperate floors, is that you ...[text shortened]... ach floor only once" mandate. The disadvantage is....well, actually there is no disadvantage.
Oh, you're talking about another problem, do you? With no floors?
Oh yes, then you have another solution also, do you?

Like:
Teacher: "When was the great earthquake at San Fransico?"
Pupil: "1969"
Teacher: "Well, not quite."
Pupil: "Perhaps, but my father was born then! So, of course the answer is right, but the question was wrong!"

One problem, one solution.
Another problem, another solution.
15. Natural Science
blunderer of pawns
30 Oct '06 00:34
Originally posted by FabianFnas
Oh, you're talking about another problem, do you? With no floors?
Oh yes, then you have another solution also, do you?

Like:
Teacher: "When was the great earthquake at San Fransico?"
Pupil: "1969"
Teacher: "Well, not quite."
Pupil: "Perhaps, but my father was born then! So, of course the answer is right, but the question was wrong!"

One problem, one solution.
Another problem, another solution.
I can explain it to you, but I can't understand it for you. You think we're talking about two completely different problems, with two completely different solutions. No. It's two different versions of the same problem. The solution is the exact same. (turn one switch on, leave one switch off, turn one switch on for a few minutes and then turn it off) The difference between the two versions is purely cosmetic.

I did a quick Google search for different versions of the problem. I found numerous versions where there were 3 lightbulbs in the next room, found one where there were 3 lightbulbs upstairs, all in the same room, and I found one where there was only one lightbulb, in the next room. Couldn't find a version where there's three lightbulbs in three seperate rooms. Every detail of a problem should exist for a reason. There's no reason that these lightbulbs all need to be in seperate rooms.