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UKMT Senior Mathematical Challenge, 2024

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

$P$ , $Q$ , $R$ , $S$ and $T$ are the digits 1, 2, 3, 4 and 5 in some order. ' $PRT$ ' and ' $QRS$ ' are both three-digit primes. Which digit is $R$ ?

(A) $1$ (B) $2$ (C) $3$ (D) $4$ (E) $5$

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