Question 644763
the codes will look like one of these:
00xx
xx00
0x0x
x0x0
x00x
0xx0 
where the x's can't be 0, but 
they can be 1-9
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So there are {{{ 9^2 = 81 }}} possible
codes for each of these 6 choices
there are 6*81 = 486 possible
codes altogether