A 2-regular graph has 7 vertices (every vertex has degree 2). How many edges |E| does it have?
Graph theory worksheet with answers
1.Easy
n = 7k = 2
|E| =
2.Easy
Exactly one vertex of the graph has degree 4. Click it.
deg = 4
- 1A
- 2B
- 3C
- 4D
- 5E
- 6F
- 7G
3.Medium
A tree has 3 vertices of degree 4, and all its other vertices are leaves (degree 1). How many leaves L does it have?
3 × deg 4
L =
4.Medium
How many different Hamilton circuits H does the complete graph K6 have? Circuits that differ only in the starting vertex or the direction count as the same.
K6
H =
5.Hard
Find the total weight W of a minimum spanning tree of the weighted graph.
|V| = 6|E| = 8
W =
6.Hard
Use Dijkstra’s algorithm to find the length d(F) of the shortest path from A to F in the weighted graph.
start: Aend: F
d(F) =
Answer key
- 1. |E| = 7
- 2. B
- 3. L = 8
- 4. H = 60
- 5. W = 31
- 6. d(F) = 27
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