Question

Consider the graph with V = [A, B, C, D, E] and E = [AX, AY, AZ, BB, CX, CY, CZ, YY]. Without drawing a picture of the graph
a. List all the vertices adjacent to Y
b. List all the edges adjacent to
c. Find the degree of Y
d. Find the sum of the degrees of the vertices

Answer 1

a.
A vertex adjacent to Y is one which is linked by an edge (∈E) to Y.
An example from the set E above would be AY. The edge YY is a loop, i.e. it links back to itself, so Y is NOT considered adjacent to Y.

b.
question incomplete.
If the question had been List all the edjacent to X, then it would be all the edges that contain at least one vertex as X:
AX, CX (∈E).

c.
The degree of a vertex is the number of edges that are incident (connected) to the vertex. Loops are counted twice for degree.

d.
Will be left for you as an exercise.