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, 2006

Number theory Difficulty 3.0 AMC 10/12 Prove it Canada

How many of the positive integers from $1$ to $100$ , inclusive, do not contain the digit $7$ ? Explain how you got your answer.

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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.