Wednesday, December 9, 2009

Light Bulb and Switches

There exists 1 light bulb and 3 independent binary switches.

The light bulb cannot be observed from the location where the switches can be manipulated.

On/Off positions for the switches are marked (known).

First, manipulate the switches. Second, observe the light bulb.

You only get to manipulate the switches once, you only get to observe the light bulb once.

Which switch controls the light bulb?

Solution in ASCII-HEX. (here's a converter)

49 6E 63 61 6E 64 65 73 63 65 6E 74 20 6C 69 67 68 74 20 62 75 6C 62 73 20 67 65 74 20 68 6F 74 2E 1F 53 65 74 20 73 77 69 74 63 68 65 73 20 28 31 2C 32 2C 33 29 20 74 6F 20 28 6F 6E 2C 6F 6E 2C 6F 66 66 29 20 61 6E 64 20 77 61 69 74 2E 1F 54 68 65 6E 20 73 65 74 20 73 77 69 74 63 68 65 73 20 28 31 2C 32 2C 33 29 20 74 6F 20 28 6F 6E 2C 6F 66 66 2C 6F 66 66 29 20 61 6E 64 20 6F 62 73 65 72 76 65 20 74 68 65 20 6C 69 67 68 74 20 62 75 6C 62 2E 1F 49 66 20 69 74 20 69 73 20 6F 6E 20 74 68 65 6E 20 73 77 69 74 63 68 20 23 31 20 63 6F 6E 74 72 6F 6C 73 20 74 68 65 20 6C 69 67 68 74 20 62 75 6C 62 2E 1F 49 66 20 69 74 20 69 73 20 6F 66 66 20 61 6E 64 20 77 61 72 6D 20 74 68 65 6E 20 73 77 69 74 63 68 20 23 32 20 63 6F 6E 74 72 6F 6C 73 20 74 68 65 20 6C 69 67 68 74 20 62 75 6C 62 2E 1F 49 66 20 69 74 20 69 73 20 6F 66 66 20 61 6E 64 20 63 6F 6C 64 20 74 68 65 6E 20 73 77 69 74 63 68 20 23 33 20 63 6F 6E 74 72 6F 6C 73 20 74 68 65 20 6C 69 67 68 74 20 62 75 6C 62 2E
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