Each bulb is switched off at present.
Three switches outside a windowless room.
The warmer of the two.
Switch on the first switch leave it for a minute and then switch it off again.
A windowless room contains three identical light fixtures each containing an identical light bulb or light globe.
How can you determine which switch is connected to which bulb if you are only allowed to enter the room once.
You are outside the room and the door is closed.
Feel the two bulbs that are not lit.
Then switch on the second switch and enter the room.
Three switches outside a windowless room are connected to three light bulbs inside the room.
Then switch on the second switch and enter the room.
Turn the first two switches on and leave them on for 2 minutes.
Each light is connected to one of three switches outside of the room.
Switch on the first switch leave it for a minute and then switch it off again.