The number of different spanning trees in complete graph, K4 and bipartite…

2016

The number of different spanning trees in complete graph, K4 and bipartite graph, K2, 2 have ______ and _______ respectively.

  1. A.

    14, 14

  2. B.

    16, 14

  3. C.

    16, 4

  4. D.

    14, 4

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Show answer & explanation

Correct answer: C

Answer: 16 for K4 and 4 for K_{2,2}.

Reason:

For a complete graph K_n, use Cayley's formula:

  • Number of spanning trees = n^{n-2}.

  • For K4: n = 4, so number = 4^{4-2} = 4^2 = 16.

For a complete bipartite graph K_{m,n}, use the formula:

  • Number of spanning trees = m^{n-1} * n^{m-1}.

  • For K_{2,2}: m = 2, n = 2, so number = 2^{1} * 2^{1} = 4.

Therefore the correct pair of counts is 16 for K4 and 4 for K_{2,2}, matching the option showing '16, 4'.

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