# Imagine you are in a room with 3 switches

IQ Test

Imagine you are in a big house and you need to match out the 3 switches located in the first floor with the three light bulbs located in the ground floor. In the ground floor there are 3 bulbs (all are off at the moment), each switch belongs to some bulb.

Question

How can you find out, which switch belongs to which bulb?

Other conditions

It is impossible to see from one room to another.

He can only get down only once to check out the bulb.

Only hands are used. No other device.

#### Vineet Patawari

Hi, I'm Vineet Patawari. I fell in love with numbers after being scared of them for quite some time. Now, I'm here to make you feel comfortable with numbers and help you get rid of Math Phobia!

## 33 thoughts to “Imagine you are in a room with 3 switches”

1. hari says:

On a switch and the light glowing bright or normal or dim
bright near
normal middle
dim far

2. lalit says:

Just switch on any 1 bulb for 5 mins.Remeber that switch.Then switch on another bulb and go downwards.First we will get one right switch which is lightened.Then check remaining 2 bulbs.The bulb which is hot will be of first switch that we remembered.And remaining is of last switch.

3. tanveer says:

hello dude its so easy just switch on bulb A for 6 min then bulb B for 2min and then while going switch on bulb C THEN CHECK THE TEMPERATURE u can have the diffffffffffff

1. ashi says:

Tempreture of two bulb remain the same either it will on for 5mnt or 2mnt coz it takes few secod to get hot.

2. lalit says:

Its wrong procedure dear.check out mine.

4. Smartzen Musti says:

first switch A then after sometimes B and then c After that go down stairs check the wire and which was hot that is the switch

1. lalit says:

Its wrong dear check out mine instead.

5. Ashwin Singh says:

first turn on first light & then switch it off. then turn on the second light then switch it off.then turn on the third light then switch it off.now go down and check the temprature of each bulb.

6. saneesh says:

Turn on one light, turn other light for some time and keep off, dont swich on the third one and check the temperature of the second and third bulbs

7. Yogesh says:

First switch on Switch A for ten minutes.Then switch it off and switch on Switch B.Now go down the and see the bulbs.The bulb which is hot belongs to Switch A,the bulb which is glowing belongs to Switch B and the third bulb belongs to Switch C.:)

8. Ankush Singh says:

1. Switchon A and wait for 5min
2. Swithchoff A and switchon B, go to the down stair
3. The ON bulb belongs to switch B, hot wired bulb belongs to switch A and cold wired belongs to switch C… ๐

1. lalit says:

Nice thats the right answer.

2. Arindam Das says:

good…. ๐ very good. i m impressed

9. Kanchan says:

Switch on A for 5-10 minutes and then for 1-2 minutes switch on B. After this switch off both. Then go downstairs and check which one is more among the three, that bulb corresponds to A, next you can check for B and C.
One more solution to this problem is that you can take somebody’s help by keeping him/her on the ground floor.

10. ISHWAR says:

not so difficult many answers are same and right i.e. switch on for 5 to 10 minutes

11. hey dude nice question but I Can solve it with some of good argue explanations… can you provide the size of every wires which is used to connect every bulbs and switches

12. Nilesh says:

switch on A for 5-10 min, then switch it off. Now put on the switch B for just 10 sec . Now check the bulbs. The bulb which is hottest corresponds to switch A, and the bulb which is coldest corresponds to switch C and the other one belongs to Switch B.

13. Ayush garg says:

Switch on A and B go down and watch you will find any two bulbs glowing suppose first and third are glowing so come back and switch off A and Switch on Second now one of the bulb would go off and the second bulb along with the previous one would be there lit up thus after this you can find the exactly which bulb belongs to which switch

14. VINAY says:

SIR PLEASE PROVIDE THE PROOF OF PYTHAGORAS THEORM IN MATHEMATICS viz.
H2 = B2 + P2 & The area of traingle formed by joining mid points of the sides of a given triangle is one-fourth of the area of the given Traingle .

15. VINAY says:

SIR PLEASE PROVIDE THE PROOF OF PYTHAGORAS THEORM IN MATHEMATICS viz.
H2 = B2 + P2 & The area of traingle formed by joining mid points of the sides of a given triangle is one-fourth of the area of the given Traingle .

16. sawal says:

1. switch on A and B
2. go and check bulb
3. again switch off any one.
3. go and watch to find answer.
(A. B. is on then only c in remaining, so u find “c” and when u off “B” u will find that too. so last one is “A” )

1. sawal says:

really that is one mistake one watching.

1. on “A” and “B” 5 to 10 min.
2. off the “B”
3. watch what is on (A), bulb with hot wire is (B) and cold one is (C)

lol.

17. avan says:

first switch on the bulb A for some time (5-10 min).and switch off it and now switch on the bulb B.go downstairs,touch two off bulbs which one is hot belongs to switch A.and the bulb which glows belongs to switch B.and the remaining one belongs to switch C

18. sangeeta says:

switch on A for some time (say, 5 min)and switch off it and switch on B and immediately come down and touch the two off bulbs.the bulb which is hot among these two bulb is linked to switch A and the on bulb is linked with switch B and the other switch off bulb is linked with the switch C.

19. Hareesh Panakkal says:

First switch on bulb1 for 5 minutes and switch off it and switch on bulb2.
Now go down and touch off two bulbs and heated one will be one which
switch on first.Glowing bulb is the second one switched on and remaining is for the bulb3

20. sanjeev says:

swith on A for 5-10 min, then switch it off. Now put on the switch B for just 10 sec . Now check the bulbs. The bulb which is hottest corresponds to switch A, and the bulb which is coldest corresponds to switch C and the other one belongs to Switch B.

21. REX JOMY JOSEPH says:

Switch 1 for more than 10 minutes , then switch it off. Switch an another bulb and go down the stairs immediately to see the bulbs. The one which is hot is the bulb belonging to the first switch , the one glowing is the bulb belonging to the 2nd switch. The other one belonging to the third.

22. akhilesh says:

swith on A, then wait for some time.. then switch it off. Now put on the switch B n for just 10 sec . Now go down and touch the bulbs. The bulb which is hottest corresponds to switch A, and the bulb which is coldest corresponds to switch C and the other one belongs to Switch B.
๐

23. YOGI says:

MOHIT IS CORRECT…………I can BET

24. bulls eye ๐
absolutely correct answer mohit !!

25. Mohit says:

Very close.. Actually scientifically possible, but then practically there is a easy way:

Turn on Switch 1 for 5 minutes, and then switch it off.

Then Turn on Switch 2, and go to other room.

One bulb will be On, that will be Switch 2.

One Off bulb will be Hot, that will be Switch 1.

One cold and Off bulb will be connected to Switch 3.

26. close but not the perfect answer!

27. aswanth says:

just switch on the bulbs one after with the time delay and go the room and check the heat of the bulb according to that time lapse. we will come to know , which is belongs to which