A tree has 2n vertices of degree 1, 3n vertices of degree 2, n vertices of degree 3. Determine the…
There are V=2n+3n+n=6n vertices and E=V−1=6n−1 edges. The degree sum gives 2n+6n+3n=2E, so 11n=12n−2 and n=2. Hence V=12 and E=11.
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A tree has 2n vertices of degree 1, 3n vertices of degree 2, n vertices of degree 3. Determine the number of vertices and edges in tree.
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Correct answer A
There are V=2n+3n+n=6n vertices and E=V−1=6n−1 edges. The degree sum gives 2n+6n+3n=2E, so 11n=12n−2 and n=2. Hence V=12 and E=11.
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UGC NET Computer Science and Applications