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HMMT February

Number theory Difficulty 4.8 AIME Find the answer

A product of five primes is of the form ABC,ABCA B C, A B C, where A,BA, B, and CC represent digits. If one of the primes is 491, find the product ABC,ABCA B C, A B C.

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

491⋅1001⋅2=982,982491 \cdot 1001 \cdot 2=982,982.

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