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UKMT Junior Mathematical Challenge, 2018

Number theory Difficulty 3.0 AMC 10/12 Find the answer United Kingdom

Between them, the two five-digit integers $M$ and $N$ contain all ten digits from 0 to 9. What is the least possible difference between $M$ and $N$ ?

(A) $123$ (B) $247$ (C) $427$ (D) $472$ (E) $742$

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