Question

A windowless room has 3 lightbulbs. You are outside the room with 3 switches, each controlling one of the lightbulbs. If you can only enter the room one time, how can you determine which switch controls which lightbulb

Answer 1

Turn on any one switch for 5 minutes and don't enter the room..
Now turn the first switch off and turn second switch on..
Enter the room and touch each bulb
1) The glowing bulb will be controlled by switch 2

2) The hot bulb will be controlled by switch 1

3) The cold bulb will be controlles by switch 3