Suppose there are 3 bulbs in one room. You are standing in another room where 3 switches to those bulbs are present.
Now, one of the bulb is faulty. You can go to the bulb room only once. And also can switch ON only one bulb at a time. How to find the defective bulb?

• on 1 switch for 5mintues and off it and now on another switch and go to room
  now if bulb is on then 2nd switch is correct and also touch the other two bulbs if any one is heated then 1st switch is coorect and other bulb is defective....
• 9 years agoHelpfull: Yes(8) No(1)
• only one method to find defective method ...........
  first we on one switch some tafter that off and ON seconds switch ....come to bulb and touch it is heat or not and decide
• 9 years agoHelpfull: Yes(4) No(2)