It works in any base, you can extend Benfords law to other bases easily.
Try it on a set of numbers in base 10, then convert them to base 16 and check the percentages you get. They still follow the same pattern, but of course there are more slots and the individual percentages are lower because of that.
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Only if you're using a decimal notation for binary systems (think of 1 and 0 of computers).
[Not regarding you comment or this response]
As I have understood, the Law applies only to a logarithmic scale [1 to 2, 2 to 3, 3 to 4, ... to ...]. Look at this pattern graph:
http://en.wikipedia.org/wiki/File:BenfordDensities.png
It works in any base, you can extend Benfords law to other bases easily.
Try it on a set of numbers in base 10, then convert them to base 16 and check the percentages you get. They still follow the same pattern, but of course there are more slots and the individual percentages are lower because of that.