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### Challenging Puzzle

Challenging Puzzle - 19 August

Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb ??

1. turn on 1st switcch for few min. and then turn off.... turn on second switch ..enter the room ..if bulb is on then obviuosly second switch....if not then touch it through hand if the bulb is heated the switch is 1st one, o/w third switch is for bulb

1. thats a good one

2. that is really clever

4. or if only one is wired to the bulb than turn them all on! or if u wanna know which light switch turns on the bulbs open the door but don't enter and flip on and off the light switches.

5. ill prove abhishek wrong. heres how: hes a dumb idiot because he is a pain in the butthole or as you would call it a pain in the behind!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

6. configure all the swiches to the one room

7. youre assuming the bulb was not already lit prior to hitting any swtich

8. youre assuming the bulb was not already lit prior to hitting any swtich

9. Or you can flip one switch at a time and dont open the door just look underneath it to see if the room lit up this way you dont have to open the door

10. Um... Just look in, but don't actually go in. Then just flip switches around until the light turns on.

11. what if the light was on to start with? then it would be hoot

12. Re read the question, it says each switch has on OR off. Not on and off. So obviously you'd look for the one with on.

13. First , reverse 1st two switches, and go in side. Check whether the bulb is hot, then if it is Hot, break the glass and come back and reverse any of the one from the first two, If you here the fusing sound, thats it..

14. actually abhishek ur correct but u did not express it well.the answer to the riddle is :switch on the 1st switch leave it on for 2 mins and switch it of and do the same with the other two.then enter the room touch the the light bulbs.the light bulb which is cold would be connected to the first switch the light bulb which is warm woud be connected to the second and light bulb that is hot is connected to the last switch

15. nicely done Bro..

2. Set the first switches on for abt 10min, and then switch on the second switch and then enter the room.
Three cases are possible
1.Bulb is on => second switch is the ans
2.Bulb is off and on touching bulb , you will find bulb to be warm
=>1st switch is the ans.
3.Bulb is off and on touching second bulb , you will find bulb to be normal(not warm)
=>3rd bulb is the ans.

1. This is weird ! y are microsoft ppl asking such questions - i dont understand its connection wuth the technical work at all

2. Neha totally copied the solution the exact punctuation and symbols WOW!!!

3. frm where does 2nd nd 3rd bulb came.

4. Any of the switch could be the right one.
look into the room through the door or any other openings into the room. Try each switch to get the right one. then you can enter an illuminated room.

5. remove the switch board that covers the switches and check which wire connected to the swtich belong to the bulb ....simple !!!!

1. This is not correct answer.Think again on it ....

2. How is that not a right answer? It doesn't violate any rules. It's actually pretty clever.

6. switch on two bulbs at a go since the fact is two might be ON or two might be OFF.

7. first switch on all the switches, then go near the door of the room, look inside the room from the door side, whether bulb is lightning or not... then switch off the switches one by one, every time look inside the room, the one got the bulb off is the controller of the bulb...

1. yeah but you can only go into the room once so that wouldn't work

2. not correct answer, bz u have to in side room only one time but u r looking every time here....so this is wrong way

8. ya i agree with honey

9. Switch on 1 for some time then switch it of, then turn on 2 and remember 3 is off all the time.
If bulb is hot den ans is 1
If glowing then ans is 2
If none of the above happens then 3.

10. You are already in the room with the switches and the one light bulb so that you can take your time and try each switch one a time.You will eventually get the correct switch.

1. no you're not

2. lol i read this and i thought it said 'You are already in the room with the 'sandwitches' I'm like... Jelly, i want a sandwitch xD

11. Only one switch is for a bulb inside of the room so see what comes on outside of the room after turing on the switches in the hallway. The one that you see no change on the outside must be for the light on the inside. Most european homes are actually like this, lights for rooms are typically outside of the room itself.

12. All you have to do is make sure all the switches are "Off" then open the door (do not enter) and check each switch individually.

13. Just switch everything ON, and enter like a boss.

1. Nw bulb 4 u......

14. 1. Turn first switch on for 10-15 minutes. Then turn it off.
2. Turn the second switch on.
3. Enter the room. Touch the bulb. If it is warm and off, it's the first switch. If it's on, it's the second one. If it's off and cold/room temperature, it's #3.
Simple!

15. IF you Enter the room first to verify status of bulb
and then changing status of switches will give more easy determination of correct operating switch

1. just turn on all three switches

16. turn on all 3... it will activate the bulb... so care wich it is as long as the bulb is on... unless the others activate some sort of death-ray or something noone will care if they are left on...

17. provided the bulb is at a reachable height!

1. haha, yeah no one ever thought of that..

18. u leave the first switch on for 30 minutes and switch it off then switch the 2nd one on and go in the room. If it is off but warm it is the 1st.If it is off and cold it is the 3rd. If it is on it is the 2nd

19. It said you cant enter the room... It never said you cant just look in through the doorway lolz :D

20. leave the door open...

21. Turn one light on for several minutes, then turn it back off. Turn another one on and go back upstairs. The light that is on that is hotter was the first switch that was on, the the light that is on that is cooler is the second swithc, making the light that is off the final one

22. Wait till nighttime
You should be able to see the difference between all switches by looking for (wait for it) LIGHT

1. It would all be in vain if the light bulb was broken

23. wow someones house needs a remodel

24. Three switches for the light bulbs outside the room and only one for the bulb that is inside the room. It means if I switch on two switches it will make the bulbs ON that are outside the room and the third switch will offcourse for the bulb that is inside! make life simple :)

25. how come one assume that the bulb is switched off... it may in on status too..right?? they didn't mention anything about tat??

26. Why dont you just OPEN the door and not go inside and just see which switch works?

27. Turn on switch "A" for 4.7 minutes. Turn it off and turn on switch "B". Open the door and touch the light bulb.

if the light is on, it is "B"
if the light is off and hot, it is "A"
if the light is off and cold, it is "C"

28. Turn on switch "A" for few minutes. Turn it off and turn on switch "B". Open the door and touch the light bulb.

if the light is on, it is "B"
if the light is off and hot, it is "A"
if the light is off and cold, it is "C"

29. leave the door open

30. Open the door to the room and try each of the switches. When the light goes on/off, you know which switch caused it, then enter the room.

31. It's fantastic that you are getting thoughts from this piece of writing as well as from our discussion made at this place.
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32. TURN ON ALL SWITCHES!

33. Last year i went to my grandparents house for chirstmas and we ate a meal an d my grandmother gave me a ceramic vase

1. was the ceramic vase tasty though?

2. HA HA HA!!!!!

34. This comment has been removed by the author.

35. turn them all on...

36. *Im going to answer if it is a normal door in a house*

Well like i said if its a normal door you found in the common house then it should be able to tell which switch turns on the light in the other room before you open it. First turn off or down the lights in the room you are currently in and make sure all the switches are on off, then proceed to turn each switch on one at a time when you turn the right switch on you should see small rim of like coming from one edge of the door. The reason you see the dim light coming from an edge of the door is because you have the lights either turned off or down which in turn would allow you to see the small amount of light coming from the door that you normally wouldn't see if the lights in the current room are on.

1. While this Answer may not be the intended answer it is still viable as ive tested the dim light at the bottom of the door *if the door to the other room is a normal house door that is* and it would be effective...nice to see someone with slightly different way of thinking.

2. no you poobrain asshole!! bshgdjsh

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38. just have the door open and look which switch makes the light go on without entering.

39. wow realy intresting

40. Leave the door open and switch on each switch until the light comes on. Enter the room and jump up and down in victory.

41. You could look under the door

42. Well the question is there any light bulb open outside the room (you can't see the switches if there is no light in that place) if there is,Look at the switches that is set on or off if you saw a switch that is turned off switch it on and you just solved it!!

43. well i have seen a few versions of this question one with 3 bulbs and the bulbs in an attic with switches in a basement
the trick is to leave one light switch on turn one on leave it then turn it off and leave the last one off
if it is on when you enter it was the first switch toggled
if it is off but warm it was the second switch
if it is off and cold it was the third switch which was left off

44. The easiest way would be to switch on each switch slowly anytime electricity make a connection there is a popping sound just use your ears and walk into the lit room...

45. heres what: beat the living crap out of the guy asking the riddle. you will then surely find out which swich operates the light bulb.

46. abhishek is correct except they forgot about the 3rd one so if the light isn't on or warm itmeans the 3rd switch is the correct one.

47. the easiest way is to turn all 3 switches ON lol

48. verify the power meeter reading for each switch before and after

49. in this solution i am using the principle that a bulb just lit is cool and a bulb lit for 10 minutees is noticebaly hot...
switch on first switch and wait for 10 minutes
switch 2 is kept in off position
put switch 3 to on AND IMMEDIATELY ENTER THE ROOM and touch the bulbs surface
1 if the bulb is very hot and is lit then first switch is true switch
2 if bulb is not hot but lit it is third switch
3 if bulb is not lit at all then secon switch

50. has anyone actually concidered, that maybe the switches were already correct and all you have to do is walk in and make a sandwitch?

51. don't turn on any of the ones outside the door. When you get inside, turn on the switch inside the door, then you can go back out to see which switch is the one that turned the light on.

52. Turn ON switch-1. wait for a minute.
Now Turn ON switch-2.
Enter room.
If the bulb is ON then switch-2
if bulb is OFF but warm then switch-1
Bulb is neither ON nor warm, then switch-3.

Assumption bulb is working.

53. Turn on all three at the same time. One of them will activate the bulb. :-)

54. Hi there guys!

Basically, I tried this and this is what happened. I flicked the first switch and left it for one minute.Then I turned it off and turned on the second switch before walking in to the room and OH MY GOD, the light was off so I couldn't see anything and accidentally tripped over a speaker cable bumping my knee on a stupid part of a subwoofer that someone idiot had left on the floor in the middle of the room and had to go to hospital so my brother figured out which switch was for the bulb before I did.

Yeah.....

55. open door and do not enter room, flick each switch till you find the right one then enter the room.

56. I assume that there is no label on the switches like ON/OFF.
Also we dont know the first status of the lamb it might be ON already, so it eliminates the heat approach.Also the bulb could be somewhere you can not reach.And i dont think you will be able to see the room while you flick switches.Because this is not a test for retards.For me this is a probabilty test.You will flick all down or up then enter the room.You have %50 chance to turn the bulb ON.Still, you never know which one is attached to the bulb unless you have tools.

57. Turn the lights off in the room with the switches and then just look under the door and you can see if the light is on in the other room.

58. You don't even need to enter a room once to see which of 3 light switches on the outside of a room turn the light on inside the room, you only need to open the door.

59. The right answer involves questions:

1. What state are the switches in (if any are in the on state then you have to turn them off as the first step)

2. Send an email to the facilities manager and inquire: What is the temperature in the room with the bulb? Whats the wattage of the light bulb?

3. Create a ticket/task for an appropriate engineer to calculate how long said light bulb with its wattage output would take to cool down completely.

4. Wait the calculated time, come back and perform the process for the answer most have seemed to figure out.

Of course you could always just .. ask the facilities manager which switch it is in the very beginning.

60. Very HOT and mild hot and room temperature
Switch on 1st button for 5 minutes. Switch on 2nd button for 1/2 minute and run down. Touch each bulb and we will know the switch based on the above three temperatures

61. on two switches 1';2 and wait for 5 min.then switch off 2 now enter the room you will find one lamp glowing other lamp off but slightly hot which is 2 obviously third for switch 3.

next time you call in a technician tell him to put light witch in the room so you know which bulbs to witch on.
simple huh?
lol

63. Turn all three switches on. Then when you enter the room see which one operates what

64. Pretty clever

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