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UKMT Senior Mathematical Challenge, 2025

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

Ayain writes down all the 3-digit numbers consisting of three different odd digits. How many of Ayain's numbers are divisible by 3?

(A) $42$ (B) $36$ (C) $30$ (D) $24$ (E) $18$

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