Question 1152468
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We can only use values from this set {0, 2} to form our four-digit numbers. Also, we must use two of each copy. 


So we have this set of possible four-digit numbers
2002
2020
2200
There are only three possible numbers we can form. 
I'm not including anything like 0220 or 0202 as these are really three digit numbers (the leading zero on the left would be ignored). I'm also ignoring 0022 for similar reasons. 


Subtract the largest and smallest values
2200 - 2002 = 198


Answer: 198
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