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.
- A.
14, 14
- B.
16, 14
- C.
16, 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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