Discrete Mathematics MCQs (Part-3)

What does the union of two sets A and B represent?

A Set difference
B All elements
C Common elements
D Subset of A

In propositional logic, which of the following is a tautology?

A (A AND B) OR (NOT A)
B A AND NOT A
C A AND (A OR B)
D A OR (A AND B)

Which of the following is true for a relation R on set A?

A R contains elements from A only
B R is a subset of B
C R is a subset of A×A
D R is a subset of A

What is the identity element for the operation of AND in Boolean algebra?

A 1
B A
C 0
D B

What is the result of (A ∩ B) ∪ (A ∩ C)?

A A ∩ B
B A ∪ (B ∩ C)
C A ∩ (B ∪ C)
D A ∩ B ∩ C

In graph theory, what does a connected graph mean?

A Contains multiple edges
B Every pair of vertices is connected
C Contains only one vertex
D Contains no cycles

Which of the following is true for a function f: A → B?

A Multiple elements in B map to one element in A
B A maps to multiple B
C Every element in B maps to one element in A
D Every element in A maps to one element in B

What does the complement of a set A represent?

A Elements outside A
B A union B
C All elements of A
D Subset of A

In Boolean algebra, what is the result of A AND NOT A?

A 0
B A
C NOT A
D 1

Which of the following graphs has no cycles?

A Complete graph
B Tree
C Directed graph
D Bipartite graph

What does the inverse of a relation mean?

A Reversing the graph
B Removing the relation
C Reversing set elements
D Swapping the order of pairs

What is the least common multiple (LCM) of 3 and 5?

A 15
B 30
C 5
D 10

What is the purpose of a truth table?

A To map functions
B To perform set operations
C To represent logical expressions
D To solve algebraic equations

What is a matrix used for in Discrete Mathematics?

A Solving linear equations
B Representing graphs
C Calculating probabilities
D Representing sets

What is the main feature of a directed graph?

A No vertices
B Multiple paths between vertices
C One direction per edge
D No edges