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Problem 670

AMC 10/12, early questions

Number theory Difficulty 3.0 Find the answer UKMT Grey Kangaroo · United Kingdom · 2019

Chloe chose a three-digit integer with all its digits different and wrote it on lots of pieces of paper. Peter picked some of the pieces of paper and added the three-digit integers on them. His answer was $2331$ . How many pieces of paper did Peter pick? (A) $2331$ (B) $21$ (C) $9$ (D) $7$ (E) $3$

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