Prove or disprove: If G = (V; E) is an undirected graph where
every vertex has degree at least 4 and u is in V , then there are
at least 64 distinct paths in G that start at u.
We say a graph is k-regular if every vertex has degree exactly
k. In each of the following either give a presentation of the graph
or show that it does not exist. 1) 3-regular graph on 2018
vertices. 2) 3-regular graph on 2019 vertices.
Suppose that a graph G is such that each vertex of G has degree
at least 100. Show that G contains a cycle of length at least 101,
i.e., a cycle passing through at least 101 vertices.
(a) What is the maximum degree of a vertex in a simple graph
with n vertices?
(b) What is the maximum number of edges in a simple graph of
n vertices?
(c) Given a natural number n, does there exist a simple
graph with n vertices and the maximum number of edges?
Discrete Mathematics
A tree contains 1 vertex of degree 2, 1 vertex of degree 3, 1
vertex of degree 4, 11 leaves and the remaining vertices have
degree 3.
Find the total number of vertices.
Sketch two non-isomorphic trees statisfying the above
mentioned conditions.
Use the fact that every planar graph with fewer than 12 vertices
has a vertex of degree <= 4 to prove that every planar graph
with than 12 vertices can be 4-colored.
A tree is a circuit-free connected graph. A leaf is a vertex of
degree 1 in a tree. Show that every tree T = (V, E) has the
following properties: (a) There is a unique path between every pair
of vertices. (b) Adding any edge creates a cycle. (c) Removing any
edge disconnects the graph. (d) Every tree with at least two
vertices has at least two leaves. (e) | V |=| E | +1.