OA Exams

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  • November 15, 2024

Question 21

Which of the following is true for the adjacency matrix of an undirected graph?

a) It is symmetric
b) It is always invertible
c) It is diagonal
d) It has all elements equal to zero

Correct Answer: a) It is symmetric

Explanation: The adjacency matrix of an undirected graph is symmetric because the graph has undirected edges, meaning the edge from A to B is the same as the edge from B to A.

Question 22

What is the degree of a vertex in a graph?

a) The number of edges incident to the vertex
b) The number of vertices adjacent to the vertex
c) The number of loops in the graph
d) The number of vertices in the graph

Correct Answer: a) The number of edges incident to the vertex

Explanation: The degree of a vertex is the number of edges that are incident to it, representing how many edges connect to that vertex.

Question 23

Which of the following describes a simple graph?

a) A graph with no loops or parallel edges
b) A graph with loops but no parallel edges
c) A graph with parallel edges but no loops
d) A graph with both loops and parallel edges

Correct Answer: a) A graph with no loops or parallel edges

Explanation: A simple graph is a graph that contains no loops (edges that connect a vertex to itself) and no parallel edges (multiple edges connecting the same pair of vertices).

Question 24

What does the term “isolated vertex” refer to in graph theory?

a) A vertex that is not connected to any other vertex
b) A vertex that is connected to all other vertices
c) A vertex that has exactly one neighbor
d) A vertex that is part of a cycle

Correct Answer: a) A vertex that is not connected to any other vertex

Explanation: An isolated vertex is a vertex that has no edges connecting it to any other vertices in the graph.

Question 25

Which of the following describes an Euler circuit?

a) A circuit that visits every edge of a graph exactly once and returns to the starting vertex
b) A path that visits every vertex of a graph exactly once
c) A cycle that visits every vertex of a graph exactly once
d) A path that visits every edge of a graph exactly once but does not return to the starting vertex

Correct Answer: a) A circuit that visits every edge of a graph exactly once and returns to the starting vertex

Explanation: An Euler circuit is a closed path that visits every edge of a graph exactly once and returns to the starting vertex.

Question 26

Which of the following describes a Hamiltonian path?

a) A path that visits every vertex of a graph exactly once
b) A path that visits every edge of a graph exactly once
c) A path that starts and ends at the same vertex
d) A path that has no repeated vertices or edges

Correct Answer: a) A path that visits every vertex of a graph exactly once

Explanation: A Hamiltonian path is a path that visits every vertex of a graph exactly once without revisiting any vertices.

Question 27

Which of the following is a key property of a bipartite graph?

a) Its vertex set can be divided into two disjoint sets such that no two vertices within the same set are adjacent
b) It contains exactly two cycles
c) It contains parallel edges between two vertices
d) It has an equal number of edges and vertices

Correct Answer: a) Its vertex set can be divided into two disjoint sets such that no two vertices within the same set are adjacent

Explanation: A bipartite graph is a graph whose vertices can be divided into two disjoint sets such that no two vertices within the same set are adjacent.

Question 28

What does the Pigeonhole Principle state?

a) If n+1 or more objects are placed into n boxes, at least one box must contain more than one object
b) If n+1 or more objects are placed into n boxes, each box will contain exactly one object
c) If n objects are placed into n+1 boxes, at least one box will contain more than one object
d) If n objects are placed into n+1 boxes, each box will contain at least one object

Correct Answer: a) If n+1 or more objects are placed into n boxes, at least one box must contain more than one object

Explanation: The Pigeonhole Principle states that if more objects than containers are available, at least one container must hold more than one object.

Question 29

Which of the following is true for a permutation of a set?

a) It is an ordered arrangement of all elements in the set
b) It is an unordered selection of elements from the set
c) It is a subset of the set
d) It is a multiset where elements may repeat

Correct Answer: a) It is an ordered arrangement of all elements in the set

Explanation: A permutation of a set is an ordered arrangement of all the elements in the set.

Question 30

Which of the following describes an r-combination of a set?

a) An unordered selection of r elements from the set
b) An ordered arrangement of r elements from the set
c) A subset of the set
d) A multiset where elements may repeat

Correct Answer: a) An unordered selection of rrr elements from the set

Explanation: An r-combination of a set is an unordered selection of r elements from the set, where order does not matter.

Question 31

Which of the following describes a power set?

a) The set of all subsets of a given set
b) The set of all elements in a universal set
c) The set of all proper subsets of a given set
d) The set of all ordered pairs in a Cartesian product

Correct Answer: a) The set of all subsets of a given set

Explanation: The power set of a set is the set of all its subsets, including the empty set and the set itself.

Question 32

Which of the following describes the union of two sets?

a) The set of all elements that are in either set or in both sets
b) The set of elements that are in both sets
c) The set of elements that are in the first set but not the second set
d) The set of elements that are in the second set but not the first set

Correct Answer: a) The set of all elements that are in either set or in both sets

Explanation: The union of two sets is the set of all elements that are in either set or in both sets.

Question 33

Which of the following describes the intersection of two sets?

a) The set of elements that are in both sets
b) The set of elements that are in either set
c) The set of elements that are in the first set but not the second set
d) The set of elements that are in the second set but not the first set

Correct Answer: a) The set of elements that are in both sets

Explanation: The intersection of two sets is the set of elements that are common to both sets.

Question 34

What is the complement of a set?

a) The set of all elements in the universal set that are not in the given set
b) The set of all elements in the given set that are also in another set
c) The set of all elements in both the given set and the universal set
d) The set of all elements that are in both the universal set and the complement set

Correct Answer: a) The set of all elements in the universal set that are not in the given set

Explanation: The complement of a set is the set of all elements in the universal set that are not in the given set.

Question 35

Which of the following describes a Cartesian product?

a) The set of all ordered pairs formed by taking one element from each of two sets
b) The set of all elements common to both sets
c) The set of all elements in the union of two sets
d) The set of all subsets of two sets

Correct Answer: a) The set of all ordered pairs formed by taking one element from each of two sets

Explanation: The Cartesian product of two sets is the set of all ordered pairs formed by taking one element from the first set and one from the second set.

Question 36

What is the principle of inclusion-exclusion?

a) A formula used to calculate the size of the union of two or more sets by subtracting the sizes of the intersections
b) A formula used to calculate the size of the union of two sets by adding the sizes of both sets
c) A formula used to calculate the size of the complement of a set
d) A formula used to calculate the size of a power set

Correct Answer: a) A formula used to calculate the size of the union of two or more sets by subtracting the sizes of the intersections

Explanation: The principle of inclusion-exclusion is a formula used to calculate the size of the union of two or more sets by subtracting the sizes of their intersections.

Question 37

Which of the following describes a free variable in a predicate?

a) A variable that is not bound by a quantifier
b) A variable that is bound by a quantifier
c) A variable that does not affect the truth value of the predicate
d) A variable that is always false

Correct Answer: a) A variable that is not bound by a quantifier

Explanation: A free variable in a predicate is a variable that is not bound by a quantifier, meaning it can take on any value within its domain.

Question 38

Which of the following describes a bound variable in a predicate?

a) A variable that is bound by a quantifier
b) A variable that is not bound by a quantifier
c) A variable that does not affect the truth value of the predicate
d) A variable that is always false

Correct Answer: a) A variable that is bound by a quantifier

Explanation: A bound variable in a predicate is a variable that is restricted by a quantifier, meaning it is associated with a specific condition or range of values.

Question 39

What does the term “tautology” mean in logic?

a) A proposition that is always true
b) A proposition that is always false
c) A proposition that is true only under certain conditions
d) A proposition that has no truth value

Correct Answer: a) A proposition that is always true

Explanation: A tautology is a proposition that is always true, regardless of the truth values of its individual components.

Question 40

Which of the following best describes a contradiction in logic?

a) A proposition that is always false
b) A proposition that is always true
c) A proposition that is sometimes true and sometimes false
d) A proposition that has no truth value

Correct Answer: a) A proposition that is always false

Explanation: A contradiction is a proposition that is always false, regardless of the truth values of its individual components.

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