Question 555405
If X represents an unknown digit which is either 4,5, or 6,
then I am given:
(1) 4 X 4
(2) 5 X X 5
(3) 2 X X X 2
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Thje problem is how to shift these 3 sequences around
so that the X's are masked out by the digits
Suppose I combine (2) and (3) this way:
5 2 X 5 X 2
Now I can combine this with (1) to mask out the X's
5 2 4 5 4 2
answer