top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration

Facebook Login
Site Registration

You are standing in front of a room with one light bulb inside of it. You can not see if it is on or off................

0 votes
96 views

You are standing in front of a room with one light bulb inside of it.
You can not see if it is on or off.
Outside the room there are three switches in the off positions.
You may turn the switches any way you want to.
You stop turning the switches, enter the room and know which switch controls the light bulb. how?

posted Aug 22, 2018 by Tapesh Kulkarni

Share this puzzle
Facebook Share Button Twitter Share Button LinkedIn Share Button

2 Answers

0 votes

Switch 1- leave off
Switch 2- turn on and leave for a minute or so to warm up the bulb, turn off
Switch 3- turn on and enter the room
If light is on- it's linked to switch 3, if light is off and bulb is warm- it's linked to switch 2, if light is off and bulb is cold- it's linked to switch 1.

answer Aug 22, 2018 by Hanifa Mammadov
0 votes

the switches were already turned off so it was easy to know how to turn it on.

answer Aug 23, 2018 by Nina Gloria



Similar Puzzles
+5 votes

A light bulb is hanging in a room. Outside of the room, there are three switches, of which only one is connected to the lamp. In the starting situation, all switches are 'off' and the bulb is not lit.If it is allowed to check in the room only once to see if the bulb is lit or not (this is not visible from the outside), how can you determine with which of the three switches the light bulb can be switched on?

0 votes

There are 3 switches downstairs, each corresponding to one of the light bulbs upstairs.
How can you figure out which light switch goes to which light bulb by only making 1 trip upstairs?

0 votes

You are standing outside a closed door. On the other side of the door is a room that has three light bulbs in it. The room is completely sealed off from the outside. It has no windows and nothing can get in or out except through the door. On the outside of the room there are three light switches that control each of the respective light bulbs on the other side of the door.

Your assignment is to determine which light switch controls which light bulb. You are allowed to enter the room only once, and once you come out, you must be able to state with 100% certainty which light switch controls which light bulb.

+1 vote

You are stuck with a gangster who likes to play it rough. The only way to survive is to accept his invitation to play Russian Roulette.

He presents a revolver in which, three bullets have been placed consecutively. Now he spins the chamber cylinder of the gun. The cylinder wont be spun again. The gun will be passed between both of you till the gun fires and one of you is dead.

Will you prefer to go first or second if you are given a choice ?

–1 vote

It was the first day of our second semester and we were looking for our hostel room numbers allotted, we saw that one of our friend was already allotted the room number last night and he challenged us to guess his new room number. We gave following answers

135, 780, 785 and 732.

He said, “That’s amazing”, “You’ve each guessed exactly one digit correctly and in its right place!”
Now can you guess what is his room number ?

Contact Us
+91 9880187415
sales@queryhome.net
support@queryhome.net
#280, 3rd floor, 5th Main
6th Sector, HSR Layout
Bangalore-560102
Karnataka INDIA.
QUERY HOME
...