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UKMT Grey Kangaroo, 2023

Combinatorics Difficulty 3.0 AMC 10/12 Find the answer United Kingdom

Some edges of a cube are to be coloured red so that every face of the cube has at least one red edge. What is the smallest possible number of edges that could be coloured red?

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

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