If there are 3 light bulbs in a room and three switches that operate them in another room, how can you determine which switch operates which bulb while only entering each room once?
2006-09-20 06:51:51 · 8 answers · asked by wildflower0306 1 in Entertainment & Music ➔ Jokes & Riddles
Turn on one switch for an hour (switch a)
thun it of, turn on another switch (switch b)
and leave the third switch (switch c) off.
Run into the other room the light bulb that is on belongs to switch b, the one that is hot belongs to switch a, and the one that is cool belongs to switch c.
or you could look through the hole in the wall.
♣
2006-09-20 06:54:17 · answer #1 · answered by VetteLeo 6 · 4⤊ 0⤋
You have to start with a known state such as:
Light 1 = Off
Light 2 = On
Light 3 = Off
Enter the switch room and change the state of two of the switches, one that is currently off and one that is currently on. Go back into the light bulb room and note which two lights changed state.
The one that didn't change state is the one attached to the switch you didn't touch. The one that you turned on is the one attached to the lighted bulb that was previously off. The one that you turned off is the one attached to the bulb that was previously on.
2006-09-20 06:59:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Get someone to stand in one of the rooms for you and tell you. They said only you could enter once they said nothing about a third party.
2006-09-20 06:58:05 · answer #3 · answered by Osunwole Adeoyin 5 · 0⤊ 0⤋
Bring down the walls between the rooms.
2006-09-20 11:21:06 · answer #4 · answered by DONALD2210 2 · 0⤊ 0⤋
perhaps there is a window between the rooms, or you could unscrew one light, leave the other in place, and take the third with you. ;)
2006-09-20 06:57:36 · answer #5 · answered by Hero-Of-Ages 2 · 0⤊ 0⤋
From right to left all the time and the first room on left.
2006-09-20 06:53:38 · answer #6 · answered by pirateron 5 · 0⤊ 0⤋
Have your friend help you out.
2006-09-20 06:57:37 · answer #7 · answered by Limeca 4 · 0⤊ 0⤋
leave the door open
2006-09-20 06:53:40 · answer #8 · answered by Tertia 6 · 0⤊ 0⤋