Chapter 14
Thinking Mathematically · 75 exercises
Problem 5
In Exercises 5-6, draw two equivalent graphs for each description. The vertices are \(A, B, C\), and \(D\). The edges are \(A B, B C, B D\), \(C D\), and \(C C\).
3 step solution
Problem 6
Draw two equivalent graphs for each description. The vertices are \(A, B, C\), and \(D\). The edges are \(A D, B C, D C\), \(B B\), and \(D B\)
3 step solution
Problem 9
Eight students form a math homework group. The students in the group are Zeb, Stryder, Amy, Jed, Evito, Moray, Carrie, and Oryan. Prior to forming the group, Stryder was friends with everyone but Moray. Moray was friends with Zeb, Amy, Carrie, and Evito. Jed was friends with Stryder, Evito, Oryan, and Zeb. Draw a graph that models pairs of friendships among the eight students prior to forming the math homework group.
4 step solution
Problem 10
An environmental action group has six members, A, B, C, D, \(\mathrm{E}\), and F. The group has three committees: The Preserving Open Space Committee (B, D, and F), the Fund Raising Committee (B, C, and D), and the Wetlands Protection Committee (A, C, D, and E). Draw a graph that models the common members among committees. Use vertices to represent committees and edges to represent common members.
3 step solution
Problem 11
In Exercises 11-16, a graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has five vertices, and there is exactly one path from any vertex to any other vertex.
3 step solution
Problem 12
A graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has five vertices, is connected, and every edge is a bridge.
4 step solution
Problem 13
A graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has eight vertices and five edges.
3 step solution
Problem 13
In Exercises 13-18, a connected graph is described. Determine whether the graph has an Euler path (but not an Euler circuit), an Euler circuit, or neither an Euler path nor an Euler circuit. Explain your answer. The graph has 60 even vertices and no odd vertices.
4 step solution
Problem 14
A graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has nine vertices and six edges.
3 step solution
Problem 14
The graph has 60 even vertices and no odd vertices. The graph has 80 even vertices and no odd vertices.
3 step solution
Problem 15
A graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has five vertices and four edges.
3 step solution
Problem 15
In Exercises 15-18, determine the number of Hamilton circuits in a complete graph with the given number of vertices. 3
4 step solution
Problem 15
A connected graph is described. Determine whether the graph has an Euler path (but not an Euler circuit), an Euler circuit, or neither an Euler path nor an Euler circuit. Explain your answer. The graph has 58 even vertices and two odd vertices.
3 step solution
Problem 16
A graph with no loops or more than one edge between any two vertices is described. Which one of the following applies to the description? i. The described graph is a tree. ii. The described graph is not a tree. iii. The described graph may or may not be a tree. The graph has four vertices and three edges.
2 step solution
Problem 16
Determine the number of Hamilton circuits in a complete graph with the given number of vertices. 4
3 step solution
Problem 16
A connected graph is described. Determine whether the graph has an Euler path (but not an Euler circuit), an Euler circuit, or neither an Euler path nor an Euler circuit. Explain your answer. The graph has 78 even vertices and two odd vertices.
3 step solution
Problem 17
Determine the number of Hamilton circuits in a complete graph with the given number of vertices. 12
3 step solution
Problem 17
A connected graph is described. Determine whether the graph has an Euler path (but not an Euler circuit), an Euler circuit, or neither an Euler path nor an Euler circuit. Explain your answer. The graph has 57 even vertices and four odd vertices.
3 step solution
Problem 18
Determine the number of Hamilton circuits in a complete graph with the given number of vertices. 13
3 step solution
Problem 18
A connected graph is described. Determine whether the graph has an Euler path (but not an Euler circuit), an Euler circuit, or neither an Euler path nor an Euler circuit. Explain your answer. The graph has 77 even vertices and four odd vertices.
3 step solution
Problem 37
Use a tree to model the parent-child relationships in the following family: Peter has three children: Zoila, Keanu, and Sandra. Zoila has two children: Sean and Helen. Keanu has no children. Sandra has one child: Martin. Use vertices to model the people and edges to represent the parent-child relationships.
3 step solution
Problem 38
Use a tree to model the employee relationships among the chief administrators of a large community college system: Three campus vice presidents report directly to the college president. On two campuses, the academic dean, the dean for administration, and the dean of student services report directly to the vice president. On the third campus, only the academic dean and the dean for administration report directly to the vice president.
6 step solution
Problem 43
What is a tree?
3 step solution
Problem 44
If a graph is given, how do you determine whether or not it is a tree?
3 step solution
Problem 45
Describe the relationship between the number of vertices and the number of edges in a tree.
3 step solution
Problem 46
What is a subgraph?
3 step solution
Problem 47
What is a spanning tree?
3 step solution
Problem 48
Describe how to obtain a spanning tree for a connected graph.
6 step solution
Problem 48
What is a Hamilton path? How does this differ from an Euler path?
3 step solution
Problem 49
What is a Hamilton circuit? How does this differ from an Euler circuit?
3 step solution
Problem 49
In Exercises 49-52, draw a graph with the given characteristics. The graph has four even vertices.
3 step solution
Problem 50
In your own words, briefly describe how to find the minimum spanning tree using Kruskal's Algorithm.
6 step solution
Problem 50
What is a complete graph?
3 step solution
Problem 51
Describe a practical problem that can be solved using Kruskal's Algorithm.
3 step solution
Problem 51
How can you look at a graph and determine if it has a Hamilton circuit?
3 step solution
Problem 51
Draw a graph with the given characteristics. The graph has four odd vertices and at least one loop.
4 step solution
Problem 52
Describe how to determine the number of Hamilton circuits in a complete graph.
3 step solution
Problem 52
Draw a graph with the given characteristics. The graph has eight vertices and exactly one bridge.
3 step solution
Problem 53
What is a weighted graph and what are the weights?
2 step solution
Problem 53
What is a graph? Define vertices and edges as part of your description.
3 step solution
Problem 54
What is the traveling salesperson problem? What is the optimal solution?
4 step solution
Problem 54
Describe how to determine whether or not a point where two of a graph's edges cross is a vertex.
3 step solution
Problem 55
Although the Nearest Neighbor Method does not always give the Hamilton circuit for which the sum of the weights is a minimum, Kruskal's Algorithm always gives the spanning tree with the smallest possible total weight.
3 step solution
Problem 55
Describe the Brute Force Method of solving traveling salesperson problems.
4 step solution
Problem 55
What are equivalent graphs?
3 step solution
Problem 56
Why is the Brute Force Method impractical for large numbers of vertices?
3 step solution
Problem 56
Because a graph can be drawn in many equivalent ways, describe the important part in drawing a graph.
3 step solution
Problem 57
Give an example of a tree with six vertices whose degrees are \(1,1,2,2,2\), and 2 .
3 step solution
Problem 57
Describe the Nearest Neighbor Method for approximating the optimal solution to traveling salesperson problems.
4 step solution
Problem 57
What is meant by the degree of a graph's vertex and how is it determined?
4 step solution