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UKMT Junior Kangaroo, 2017

Combinatorics Difficulty 2.0 Junior Find the answer United Kingdom

Rory uses four identical standard dice to build the solid shown in the diagram. Whenever two dice touch, the numbers on the touching faces are the same. The numbers on some of the faces of the solid are shown. What number is written on the face marked with question mark? (On a standard die, the numbers on opposite faces add to $7$ .)

(A) $6$ (B) $5$ (C) $4$ (D) $3$ (E) $2$

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