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Cube Diagonal Pairs Extremes

1800SpecialistCombinatoricsGeometry

Slovenija 2008 · 2008

On every face of a cube we draw one of the two diagonals. Some of these diagonals share a vertex. Let $N$ denote the number of pairs of diagonals that have a vertex in common (each diagonal can occur in several different pairs). Find the greatest and the smallest possible values of $N$.
0 students attempted0% solvedRating 1800

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