Explore topic-wise MCQs in Discrete Mathematics.

This section includes 99 Mcqs, each offering curated multiple-choice questions to sharpen your Discrete Mathematics knowledge and support exam preparation. Choose a topic below to get started.

51.

The chromatic number of a graph is the property of ____________

A. graph coloring
B. graph ordering
C. group ordering
D. group coloring
Answer» C. group ordering
52.

In a poset (S, ⪯), if there is no element n∈S with m

A. an element n exists for which m=n
B. An element m is maximal in the poset
C. A set with the same subset of the poset
D. An element m is minimal in the poset
Answer» C. A set with the same subset of the poset
53.

In a poset P({v, x, y, z}, ⊆) which of the following is the greatest element?

A. {v, x, y, z}
B. 1
C.
D. {vx, xy, yz}
Answer» B. 1
54.

G is an undirected graph with n vertices and 26 edges such that each vertex of G has a degree at least 4. Then the maximum possible value of n is ___________

A. 7
B. 43
C. 13
D. 10
Answer» D. 10
55.

In which of the following relations every pair of elements is comparable?

A.
B. !=
C. >=
Answer» B. !=
56.

An undirected graph has 8 vertices labelled 1, 2, …,8 and 31 edges. Vertices 1, 3, 5, 7 have degree 8 and vertices 2, 4, 6, 8 have degree 7. What is the degree of vertex 8?

A. 15
B. 8
C. 5
D. 23
Answer» C. 5
57.

If the partial order of a set has at most one minimal element, then to test whether it has a non-crossing Hasse diagram its time complexity __________

A. NP-complete
B. O(n²)
C. O(n+2)
D. O(n³)
Answer» B. O(n²)
58.

Which of the following relation is a partial order as well as an equivalence relation?

A. equal to(=)
B. less than(<)
C. greater than(>)
D. not equal to(!=)
Answer» B. less than(<)
59.

Hasse diagrams are first made by ______

A. A.R. Hasse
B. Helmut Hasse
C. Dennis Hasse
D. T.P. Hasse
Answer» C. Dennis Hasse
60.

A trail in a graph can be described as ______________

A. a walk without repeated edges
B. a cycle with repeated edges
C. a walk with repeated edges
D. a line graph with one or more vertices
Answer» B. a cycle with repeated edges
61.

Let a graph can be denoted as ncfkedn a kind of ____________

A. cycle graph
B. line graph
C. hamiltonian graph
D. path graph
Answer» B. line graph
62.

A ______ in a graph G is a circuit which consists of every vertex (except first/last vertex) of G exactly once.

A. Euler path
B. Hamiltonian path
C. Planar graph
D. Path complement graph
Answer» C. Planar graph
63.

A walk has Closed property if ____________

A. v₀=vₖ
B. v₀>=vₖ
C. v < 0
D. vₖ > 1
Answer» B. v₀>=vₖ
64.

The sum of an n-node graph and its complement graph produces a graph called _______

A. complete graph
B. bipartite graph
C. star graph
D. path-complement graph
Answer» B. bipartite graph
65.

In a directed weighted graph, if the weight of every edge is decreased by 10 units, does any change occur to the shortest path in the modified graph?

A. 209
B. 65
C. 57
D. 43
Answer» D. 43
66.

Which algorithm efficiently calculates the single source shortest paths in a Directed Acyclic Graph?

A. topological sort
B. hash table
C. binary search
D. radix sort
Answer» B. hash table
67.

Determine the edge count of a path complement graph with 14 vertices.

A. 502
B. 345
C. 78
D. 69
Answer» D. 69
68.

A graph is ______ if and only if it does not contain a subgraph homeomorphic to k₅ or k₃,₃.

A. bipartite graph
B. planar graph
C. line graph
D. euler subgraph
Answer» C. line graph
69.

The _______ of a graph G consists of all vertices and edges of G.

A. edge graph
B. line graph
C. path complement graph
D. eulerian circuit
Answer» E.
70.

Let G(V, E) be a directed graph where every edge has weight as either 1, 2 or 5, what is the algorithm used for the shortest path from a given source vertex to a given destination vertex to get the time complexity of O(V+E)?

A. BFS
B. DFS
C. Binary search
D. Radix sort
Answer» B. DFS
71.

Every Isomorphic graph must have ________ representation.

A. cyclic
B. adjacency list
C. tree
D. adjacency matrix
Answer» E.
72.

A cycle on n vertices is isomorphic to its complement. What is the value of n?

A. 5
B. 32
C. 17
D. 8
Answer» B. 32
73.

An isomorphism of graphs G and H is a bijection f the vertex sets of G and H. Such that any two vertices u and v of G are adjacent in G if and only if ____________

A. f(u) and f(v) are contained in G but not contained in H
B. f(u) and f(v) are adjacent in H
C. f(u * v) = f(u) + f(v)
D. f(u) = f(u)² + f(v)²
Answer» C. f(u * v) = f(u) + f(v)
74.

How many perfect matchings are there in a complete graph of 10 vertices?

A. 60
B. 945
C. 756
D. 127
Answer» C. 756
75.

A graph which has the same number of edges as its complement must have number of vertices congruent to ______ or _______ modulo 4(for integral values of number of edges).

A. 6k, 6k-1
B. 4k, 4k+1
C. k, k+2
D. 2k+1, k
Answer» D. 2k+1, k
76.

A graph G has the degree of each vertex is ≥ 3 say, deg(V) ≥ 3 ∀ V ∈ G such that 3|V| ≤ 2|E| and 3|R| ≤ 2|E|, then the graph is said to be ________ (R denotes region in the graph)

A. Planner graph
B. Polyhedral graph
C. Homomorphic graph
D. Isomorphic graph
Answer» C. Homomorphic graph
77.

A complete n-node graph Kn is planar if and only if _____________

A. n ≥ 6
B. n² = n + 1
C. n ≤ 4
D. n + 3
Answer» D. n + 3
78.

What is the grade of a planar graph consisting of 8 vertices and 15 edges?

A. 30
B. 15
C. 45
D. 106
Answer» B. 15
79.

A _______ is a graph with no homomorphism to any proper subgraph.

A. poset
B. core
C. walk
D. trail
Answer» C. walk
80.

The 2ⁿ vertices of a graph G corresponds to all subsets of a set of size n, for n>=4. Two vertices of G are adjacent if and only if the corresponding sets intersect in exactly two elements.

A. n+2
B. 3ⁿ/²
C.
D. 2ⁿ
Answer» C. n²
81.

Let G be an arbitrary graph with v nodes and k components. If a vertex is removed from G, the number of components in the resultant graph must necessarily lie down between _____ and _____

A. n-1 and n+1
B. v and k
C. k+1 and v-k
D. k-1 and v-1
Answer» E.
82.

The minimum number of edges in a connected cyclic graph on n vertices is _____________

A. n – 1
B. n
C. 2n+3
D. n+1
Answer» C. 2n+3
83.

The maximum number of edges in a 8-node undirected graph without self loops is ____________

A. 45
B. 61
C. 28
D. 17
Answer» D. 17
84.

Any subset of edges that connects all the vertices and has minimum total weight, if all the edge weights of an undirected graph are positive is called _______

A. subgraph
B. tree
C. hamiltonian cycle
D. grid
Answer» C. hamiltonian cycle
85.

G is a simple undirected graph and some vertices of G are of odd degree. Add a node n to G and make it adjacent to each odd degree vertex of G. The resultant graph is ______

A. Complete bipartite graph
B. Hamiltonian cycle
C. Regular graph
D. Euler graph
Answer» E.
86.

A bridge can not be a part of _______

A. a simple cycle
B. a tree
C. a clique with size ≥ 3 whose every edge is a bridge
D. a graph which contains cycles
Answer» B. a tree
87.

______ is the maximum number of edges in an acyclic undirected graph with k vertices.

A. k-1
B.
C. 2k+3
D. k³+4
Answer» B. k²
88.

Let G be a directed graph whose vertex set is the set of numbers from 1 to 50. There is an edge from a vertex i to a vertex j if and only if either j = i + 1 or j = 3i. Calculate the minimum number of edges in a path in G from vertex 1 to vertex 50.

A. 98
B. 13
C. 6
D. 34
Answer» D. 34
89.

What is the number of vertices in an undirected connected graph with 39 edges, 7 vertices of degree 2, 2 vertices of degree 5 and remaining of degree 6?

A. 11
B. 14
C. 18
D. 19
Answer» D. 19
90.

In a finite graph the number of vertices of odd degree is always ______

A. even
B. odd
C. even or odd
D. infinite
Answer» B. odd
91.

The graph representing universal relation is called _______

A. complete digraph
B. partial digraph
C. empty graph
D. partial subgraph
Answer» B. partial digraph
92.

What is a complete digraph?

A. connection of nodes without containing any cycle
B. connecting nodes to make at least three complete cycles
C. start node and end node in a graph are same having a cycle
D. connection of every node with every other node including itself in a digraph
Answer» E.
93.

A directed graph or digraph can have directed cycle in which ______

A. starting node and ending node are different
B. starting node and ending node are same
C. minimum four vertices can be there
D. ending node does not exist
Answer» C. minimum four vertices can be there
94.

The graph given below is an example of _________

A. non-lattice poset
B. semilattice
C. partial lattice
D. bounded lattice
Answer» B. semilattice
95.

Let, D = be a directed graph or digraph,then D’ = is a subgraph if ___________

A. A’ ⊂ A and R’ = R ∩ (A’ x A’)
B. A’ ⊂ A and R ⊂ R’ ∩ (A’ x A’)
C. R’ = R ∩ (A’ x A’)
D. A’ ⊆ A and R ⊆ R’ ∩ (A’ x A’)
Answer» B. A’ ⊂ A and R ⊂ R’ ∩ (A’ x A’)
96.

The graph is the smallest non-modular lattice N₅. A lattice is _______ if and only if it does not have a _______ isomorphic to N₅.

A. non-modular, complete lattice
B. moduler, semilattice
C. non-modular, sublattice
D. modular, sublattice
Answer» E.
97.

A simple graph can have _______

A. multiple edges
B. self loops
C. parallel edges
D. no multiple edges, self-loops and parallel edges
Answer» E.
98.

Degree of a graph with 12 vertices is _______

A. 25
B. 56
C. 24
D. 212
Answer» D. 212
99.

Disconnected components can be created in case of ___________

A. undirected graphs
B. partial subgraphs
C. disconnected graphs
D. complete graphs
Answer» D. complete graphs