# Discrete Mathematics MCQ Quiz

Discrete Mathematics is the study of Discrete objects. Here you can online practice Discrete Mathematics using this quiz. Test your maths knowledge with selective and important questions of Discrete Math.

Question 1. Which of the following is a subset of set {1, 2, 3, 4}?

(A) {1, 2, 3}

(B) {1}

(C) {1, 2}

(D) All of the mentioned

(D) All of the mentioned

Explanation: The subset of set (1, 2, 3, 4} is {1, 2}, {1, 2, 3}, and {1}.

Question 2. Which among the following can be taken as the discrete object?

(A) Rational numbers

(B) People

(C) Integers

(D) All of the mentioned

(D) All of the mentioned

Explanation: Discrete object includes people, houses, rational numbers, integers, automobiles

Question 3. Which of the following function is also referred to as an injective function?

(A) Onto

(B) One-to-One

(C) Many-to-one

(D) None of the mentioned

(B) One-to-One

Explanation: An injective function or one-to-one function is a function that connects a single element of domain to the single element of co-domain.

Question 4. What is Floor function?

(A) It maps the real number to the smallest following integer

(B) It maps the real number to the smallest previous integer

(C) It maps the real number to the greatest previous integer

(D) None of the mentioned

(A) It maps the real number to the smallest following integer

Explanation: Floor function f(x) maps the real number x to the smallest integer, which is not less than the value of x.

Question 5. Let the players who play cricket be 12, the ones who play football 10, those who play only cricket are 6, then the number of players who play only football are ____, assuming there is a total of 16 players.

(A) 8

(B) 16

(C) 10

(D) 4

(D) 4

Question 6. Mathematics can be broadly categorized into how many types?

(A) 2 Types

(B) 3 Types

(C) 4 Types

(D) 5 Types

(A) 2 Types

Explanation: Mathematics can be broadly categorized into Continuous and Discrete Mathematics.

Question 7. Convert the set x in roster form if set x contains the positive prime number, which divides 72.

(A) {2, 3}

(B) {3, 5, 7}

(C) {2, 3, 7}

(D) {∅}

(A) {2, 3}

Explanation: 2 and 3 are the divisors of 72, which are prime. So, the roster form of set x is (2, 3}.

Question 8. How many injections are defined from set A to set B if set A has 4 elements and set B has 5 elements?

(A) 64

(B) 24

(C) 120

(D) 144

(C) 120

Explanation: 20 injections are defined from set A to set B if set A has 4 elements and set B has 5 elements. Using the following formula, we can easily calculate the injections:

Number of injections from set A to Set B= 5p4

5! / (5 – 4)! = 5 x 4 x 3 x 2 = 120

Question 9. The cardinality of the Power set of the set {1, 5, 6} is____.

(A) 6

(B) 5

(C) 8

(D) 10

(C) 8

Explanation: The power set of the any set is the set of all its subset. So, P({1, 5, 6}) = {null, {1}, {5}, {6}, {1, 5}, {1,6}, {5, 6}, {1, 5, 6}}. The power set of the given set consists of 8 elements. That’s why, 8 is the cardinality of the given set

Question 10. Boolean algebra deals with how many values.

(A) It deals with only three discrete values.

(B) It deals with only two discrete values

(C) It deals with only four discrete values.

(D) It deals with only five discrete values.

(B) It deals with only two discrete values

Explanation: Boolean algebra deals with only two discrete values, 0 and 1. 0 means false, and 1 means true

Question 11. Power set of empty or Null set has exactly _________ subset

(A) Zero

(B) One

(C) Two

(D) Three

(B) One

Explanation: The power set of the Null set has exactly one subset, which is an empty set.

Question 12. The use of Boolean algebra is ____________.

(A) in building the algebraic functions

(B) in circuit theory

(C) in designing the digital computers

(D) in building the algebraic functions

(C) in designing the digital computers

Explanation: The widely use of Boolean algebra is in designing digital computers and various electronic circuits.

Question 13. How many bytes are needed for encoding 2000 bits of data?

(A) 4 Byte

(B) 2 Byte

(C) 5 Byte

(D) 8 Byte

(B) 2 Byte

Explanation: Only 2 bytes are required for encoding the 2000 bits of data

Question 14. Universal logic gate is__________.

(A) NAND

(B) OR

(C) NOT

(D) AND

(A) NAND

Explanation: NAND is a logic gate that can easily implement or create all the other logic gates without the help of three basic logic gates.

Question 15. Which case does not exist in complexity theory?

(A) Null case

(B) Best case

(C) Average case

(D) Worst Case

(A) Null case

Explanation: Average, worst, and best case are the three cases that always exist in the complexity theory. There is no Null case in the theory of complexity.

Question 16. The intersection of the sets {1, 2, 8, 9, 10, 5} and {1, 2, 6, 10, 12, 15} is the set ______

(A) {5, 6, 12, 15}

(B) {1, 6, 12, 9, 8}

(C) {1, 2, 10}

(D) {2, 5, 10, 9}

(C) {1, 2, 10}

Explanation: The intersection of the two sets is the set that contains the common elements of both the given sets. That’s why the first option is right according to the given sets.

Question 17. Which option is correct for representing an algorithm?

(A) Flow charts

(B) Statements in the common language

(C) Pseudo codes

(D) All of them

(D) All of them

Explanation: Pseudo codes, flow charts, and the statement in the common language are used for representing the algorithm.

Question 18.  In which year did Maurice Karnaughin introduce the Karnaugh map?

(A) 1953

(B) 1952

(C) 1954

(D) 1956

(A) 1953

Explanation: In the year 1953, Maurice Karnaughin invented the Karnaugh map.

Question 19. The number of reflexive closure of the relation {(0,1), (1,1), (1,3), (2,1), (2,2), (3,0)} on the set {0, 1, 2, 3} is_____.

(A) 8

(B) 36

(C) 2

(D) 6

(D) 6

Question 20. If x is a set and the set contains the real number between 1 and 2, then the set is ____.

(A) Finite set

(B) Infinite set

(C) Empty set

(D) None of the mentioned

(B) Infinite set

Explanation: X is an infinite set as there are infinitely many real numbers between 1 and 2

Question 21. Which option is the negation of the bits “1001011”?

(A) 10110100

(B) 11011011

(C) 1100100

(D) 0110100

(D) 0110100

Explanation: The negation of the given bits is the opposite value of the bits. If the value of a bit is 1 then its negation value is 0. And, if the value of a bit is 0, then its negation value is 1. That’s why the negation of “1001011” is “0110100”.

Question 22. If n(A) = 20 and n(B) = 30 and n(A U B) = 40 then n(A ∩ B) is?

(A) 10

(B) 40

(C) 20

(D) 30

(A) 10

Explanation: By using the formula we can calculate n(A ∩ B),

n(A U B) = n(A) + n(B) – n(A ∩ B).

n(A ∩ B) = n(A) + n(B) – n(A U B)

n(A ∩ B) = 20 + 30 – 40

So, n(A ∩ B) = 10

Question 23. Which of the following function is not a mathematics function?

(A) one to many

(B) one to one

(C) many to one

(D) all of the mentioned

(A) one to many

Question 24. If a and b are two positive numbers that are less than one, then the maximum value of Floor(a+b) and Ceil(a+b) is?

(A) Foor(a+b) is 1 and Ceil(a+b) is 0.

(B) Floor(a+b) is 1 and Ceil(a+b) is 2.

(C) Floor(a+b) is 0 and Ceil(a+b) is 1.

(D) Floor(a+b) is 2 and Ceil(a+b) is 1

(B) Floor(a+b) is 1 and Ceil(a+b) is 2.

Explanation: According to the question, a<1 and b<1, which means that the maximum value of Floor(a+b) is 1 and Ceil(a+b) is 2.

Question 25. How many elements in the Power set of set A= {{Φ}, {Φ, {Φ}}} ?

(A) 2 elements

(B) 5 elements

(C) 4 elements

(D) 6 elements