UKMT Pink Kangaroo, 2017

Number theory Difficulty 1.0 Junior Find the answer United Kingdom

Maria chooses two digits $a$ and $b$ and uses them to make a six-digit number $ababab$ . Which of the following is always a factor of numbers formed in this way?

(A) $2$ (B) $5$ (C) $7$ (D) $9$ (E) $11$

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