Which bulb is not working.

Puzzle:
You are standing in the first floor of the building next to 3 light switches.There is one room in the second floor of the building, where there are 3 light bulbs.Each light bulb is operated by the one of the switches next to you.Because the light bulbs are in another room you can not see them,

Now the question: One of the bulbs is not working.You can only turn on one switch and you can only make one trip to the room where the bulbs are.How to find out which bulb is not working.

Note: Don't forget to visit us again. Answer to the puzzle will be posted tomorrow with winner's name. You can provide your answer in comments.
Solution: Turn one switch on.
Case 1: If a bulb is on then the power is flowing to that bulb socket.take that bulb out and try the remaining two bulbs in the working socket.the bulb that is not working is the faulty one
Case 2:If no bulb is glowing.Take all three bulbs out.Try each bulb in 3 sockets,faulty bulb will not work in any of the socket.

Winner:

Let me enter

Puzzle:

A man is walking on the road.he saw a cool party going on.what he saw is everyone trying to enter the party is  given a set of numbers and the persons giving the correct answers are allowed to the party.

He overheard couple of numbers and correct answers
Numbers     Answers
8903   --- 4
1100   --- 2
2102   --- 1
7211   --- 0
0836   --- 4
8898   --- 7

He thinks he heard enough.He went to attend the party.
His number is 9822.He replied and he entered the party.What was his answer.


Note: Don't forget to visit us again. Answer to the puzzle will be posted tomorrow with winner's name. You can provide your answer in comments.
Solution: answer is 3 .Logic is Number of closed loops in the numbers given.
Winner: