Answer
Number of vertices = 4
Number of edges = 8
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In-degree of vertex (a) = 2
In-degree of vertex (b) = 3
In-degree of vertex (c) = 2
In-degree of vertex (d) = 1
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Out-degree of vertex (a) = 2
Out-degree of vertex (b) = 4
Out-degree of vertex (c) = 1
Out-degree of vertex (d) = 1
Work Step by Step
Vertices are simply the point in the graph. So, to count the number of vertices simply count the number of points available in the graph.
Points are a, b, c, and d. So, total number of vertices in this graph is 4.
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Edges are the path connecting the two points or vertices in the graph. So, simply count all the number of such path connecting different vertices to get the number of edges.
So total number of edges in this graph is 8.
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In-degree of a vertex is the total number of edges entering that vertex.
Note: Every loop is counted 2 times while counting degree of vertex. One time in-degree and one time out-degree.
For vertex a: 2 edges are coming in. So, in-degree is 2.
For vertex b: 3 edges are coming in. So, in-degree is 3.
For vertex c: 2 edges are coming in. So, in-degree is 2.
For vertex d: Only 1 edge is coming in. So, in-degree is 1.
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Out-degree of a vertex is the total number of edges going out of the vertex.
For vertex a: 2 edges are going out. So, out-degree is 2.
For vertex b: 4 edges are going out. So, out-degree is 4.
For vertex c: Only 1 edge is going out. So, out-degree is 1.
For vertex d: Only 1 edge is going out. So, out-degree is 1.
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