Library / /313 of 413

, 1999

Number theory Difficulty 2.0 Junior Find the answer Canada

Kalyn writes down all of the integers from $1$ to $1000$ that have $4$ as the sum of their digits. If $\frac{a}{b}$ (in lowest terms) is the fraction of these numbers that are prime, then $a+b$ is

(A) $5$ (B) $4$ (C) $15$ (D) $26$ (E) $19$

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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.