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UKMT Grey Kangaroo, 2018

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

Alice wants to write down a list of prime numbers less than 100, using each of the digits 1, 2, 3, 4 and 5 once and no other digits. Which prime number must be in her list?

(A) $2$ (B) $5$ (C) $31$ (D) $41$ (E) $53$

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