Here at Red Gate we have installed an extra security measure to help prevent unauthorised access to our Oracle server room. Our server room has no windows, the air vents on the wall are for the air conditioning units and the room (or any light in the room) cannot be seen through them, and the door is solid steel. A 21 digit code unlocks the door, but the lights (bulbs hanging on cords from the ceiling), and monitors can only be turned on by a voice command once you are inside the room. The command is either “A”, “B”, or “C”, and our DBA changes it daily without letting anyone know.
There are three switches marked A, B and C on the wall outside the door, and one of these also works the lights but only when the door is locked shut. You are allowed to touch any or all switches as often as you like before you open the door and enter the room, but once inside, you must say “A”, “B”, or “C”.
You get one chance before the server room door locks and the alarm goes off. How do you know whether A, B or C is the right command? Please post your answers below.
Note: You obviously know the code to get into the room!
12 Comments
Kev Riley
27/04/2012
Press 'A' on.
Press 'B' on, wait 30 secs, press 'B' off
Enter the room
If the lights are on, then 'A' is the right switch
If the lights are off and the bulbs are warm, then 'B' is the right switch
If the lights are off and the bulbs are cold, then 'C' is the right switch
Norman Dunbar
27/04/2012
Switch on button A.
Wait 30 seconds.
Switch off.
Switch on button B.
Open the door.
If lights are on, say "B".
If lights are off, touch bulb(s), if hot, say "A".
Say "C".
Cheers,
Norm.
Martin Giffy D'Souza
27/04/2012
Outside the room
- Hit A and leave the light on for 1 min or so (enough to warm it up)
- Turn A off and turn on B
Go into room
- If lights are on, say B
- If lights are off, touch the light bulb. If it's warm then say A, otherwise say C
Munky
27/04/2012
Press switch A and leave on for 5 minutes then off and then switch on B for 5 minutes then off. Now go in and reach up to the bulb - if it is warm, then A; if hot then B; if cold then C.
Erik van Roon
28/04/2012
Typical for DBA's.
They give you the 21 digit key to enter the server room, but make it virtualy impossible to turn on the light ;-)
Dave
05/05/2012
But wait! The bulbs are not incandescent as you mistakenly assumed, but LED instead. Without radiated heat, the touch method fails -- as does standing in the open doorway with an infrared sensor.
Option 1: Opening the outward-facing door, I attach my photovoltaic cell and wireless transmitter to the door. I close the door, having not yet entered, and cycle through the choices until the sensor detects the light energy and signals me immediately after the correct choice.
Option 2: I go to the DBA's cube and find a stick-it note on the side of the monitor, not for the 21 digit code but rather for the day's selection.
Milind
09/05/2012
I already knew the correct answer but here is another one -
1. Page on call DBA and have him send the correct code to you while you are on your way to the server room
2. Enter the room and read out the answer your on-call DBA sent you ;)
Dave
14/05/2012
Option 1)
Send the new intern in and tell him to put in the code, press 'A', and when he enters the room if the lights aren't on, to say 'B'. Tell him to report back to you.
If you hear the server-room alarm, then you know the answer is 'C'.
Option 2)
Declare @Lights_On bit
Declare @voice_command_list varchar(3)
Declare @index int
Set @Lights_On = 0
Set @voice_command_list = 'ABC'
Set @index = 1
While @Lights-On <> 1
Begin
Enter 21-digit code, press substr(@voice_command, @index, 1), open door.
If the lights are on
Begin
@Lights-On = 1
@index -= 1
End
@index += 1
Close and lock door without walking in.
End
Enter 21-digit code, open door, walk in and say substr(@voice_command, @index, 1)
Ravindra Lahane
22/05/2012
1) Press C
2) Enter server room
3) If lights are on the answer is C
4) Else say A
5) If lights are on the ans is A
6) Else the right command is B
Afterall we just want to know the correct command and has nothing to do with the alarm and other stuff :)
Jayesh
03/06/2012
If i read the puzzle correctly, it doesnt say that once you turn on the lights from outside and enter the room, the lights will turn off. Also the buttons outside are switches and so you can turn them all on - one of them will turn the lights on.
So i say...
Turn on all the switches from outside.
Unlock and enter the room.
Let the door lock shut and you have all the lights still on.
Zarif M
13/09/2012
Press Swtich A , open the door.
If the light is on it is A
Else
Before closing door, you get a chance - Press B,
If the Lights are on it is B
Else Say C before the door closes.
hemal shah
02/12/2012
First press A and check from the vents closely if u can see the light.
Try with B and C.
Even if u r not able to see the room u can see the light from the vent if its on.
So once if u come to know on which button it gets ON then get inside the room and say the letter A, B or C .
Hope its the ANSWER???
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