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, 1998

Number theory Difficulty 3.0 AMC 10/12 Find the answer Canada

The numbers 123 456 789 and 999 999 999 are multiplied. How many of the digits in the final result are 9's?

(A) $0$ (B) $1$ (C) $2$ (D) $3$ (E) $17$

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.