Tech Semiconductor Pte Interview Question: You have 3 bulbs in a room an... | Glassdoor

Interview Question

Process and Equipment Engineer Interview(Student Candidate)

You have 3 bulbs in a room and 3 switches outside. How do

  you determine which switch belongs to which bulb if you are able to enter the room once?

Interview Answer

1 Answer


Leave 2 switch off and 1 on for 5 min. Off that switch and switch on another light. Enter the room straight.
The bulb that is lighted belongs to the switch that is on after 5 min. The bulb that is warm and not lighted is the one that is switch on 5 min before. The other bulb is left untouched.

Interview Candidate on Mar 22, 2011

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