How many edges does have Prove your result Each vertex must

How many edges does have? Prove your result. (Each vertex must match to all vertices in the opposite set.)

Solution

Answer :

The complete bipartite graph K_m,n is defined by taking two disjoint sets, V₁ of size m and V₂ of size n , and putting an edge between u and v whenever u V₁ and v V₂ .

Every vertex of V₁ is adjacent to every vertex of V₂ , hence the number of edges is mn.

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