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UKMT Intermediate Mathematical Challenge, 2015

Combinatorics Difficulty 1.0 Junior Find the answer United Kingdom

A tetrahedron is a solid figure which has four faces, all of which are triangles. What is the product of the number of edges and the number of vertices of the tetrahedron?

(A) $8$ (B) $10$ (C) $12$ (D) $18$ (E) $24$

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