Challenge

CA SAHIL MITTAL (JOB) (240 Points)

09 February 2010  

There is one room. There is one bulb in the room. Three buttons are outside the room of which one is for the bulb.

If bulb is on, one can't see it from outside the room. You are standing outside the room. How will you know, which one is the button of bulb. You can go only once within the room. Reply.............

I will post the answer soon.......................