Guest Sebastian Mares Posted February 27, 2006 Posted February 27, 2006 You are alone in a house with three floors. In the third floor, there is a light bulb. In the basement, there are three switches. One switch turns the lamp in the third floor on and off while the other two switches have no function. You cannot see the third floor from the basement, nor can you see which of the three switches has a function. Your job is to find out which switch is responsible for the light bulb in the third floor. You are allowed to go upstairs only one time. How do you find out which switch turns the light bulb on and off?
volvofl10 Posted February 27, 2006 Posted February 27, 2006 switch all 3 switches ? then go and check the light is on
Movie Junkie Posted February 27, 2006 Posted February 27, 2006 (edited) You are alone in a house with three floors. In the third floor, there is a light bulb. In the basement, there are three switches. One switch turns the lamp in the third floor on and off while the other two switches have no function. You cannot see the third floor from the basement, nor can you see which of the three switches has a function. Your job is to find out which switch is responsible for the light bulb in the third floor. You are allowed to go upstairs only one time. How do you find out which switch turns the light bulb on and off? Turn on switches 1 and 2, wait a few minutes, then turn off switch 2 before going to the attic. If the bulb is off, but warm, you can conclude that switch 2 is the winner. If the bulb is on, it's switch 1. If the bulb is off, but cold, it's switch 3. GIVE ME SOMETHING DIFFICULT! Edited February 27, 2006 by Movie Junkie
Movie Junkie Posted February 27, 2006 Posted February 27, 2006 switch all 3 switches ? then go and check the light is onThat won't tell you which switch operates the light.
Guest Sebastian Mares Posted February 27, 2006 Posted February 27, 2006 Turn on switches 1 and 2, wait a few minutes, then turn off switch 2 before going to the attic. If the bulb is off, but warm, you can conclude that switch 2 is the winner. If the bulb is on, it's switch 1. If the bulb is off, but cold, it's switch 3.
Movie Junkie Posted February 27, 2006 Posted February 27, 2006 Turn on switches 1 and 2, wait a few minutes, then turn off switch 2 before going to the attic. If the bulb is off, but warm, you can conclude that switch 2 is the winner. If the bulb is on, it's switch 1. If the bulb is off, but cold, it's switch 3. Thank you.
dbminter Posted February 28, 2006 Posted February 28, 2006 I can do it without even going up the stairs at all. Use a phone, call a friend and tell him which switch you're turning on and ask him to check the bulbs.
Movie Junkie Posted February 28, 2006 Posted February 28, 2006 I can do it without even going up the stairs at all. Use a phone, call a friend and tell him which switch you're turning on and ask him to check the bulbs.
LIGHTNING UK! Posted March 2, 2006 Posted March 2, 2006 Do it the techie way and stick a multimeter in series with each switch in turn. Flick the switch on and if current it drawn, that's the one going to the bulb
lfcrule1972 Posted March 3, 2006 Posted March 3, 2006 Trust you to do it the proper way and not bodge it like the rest of us boss
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