In the name of ALLAH, the most beneficient, the most merciful

Discrete Mathematics (MTH202)

Multiple Choice Questions (MCQs)

Objective Questions

  1. Find the number of the word that can be formed of the letters of the word “ELEVEN”.

    1. 120
    2. 110
    3. 220
    4. None of the given
  2. ( p ∨ ∼p ) is the ________.

    1. Contradiction
    2. Conjunction
    3. Tautology
    4. Contingency
  3. A tree is normally constructed from ________.

    1. right
    2. center
    3. left to right
    4. right to left
  4. Which of the following statements is true according to the Division Algorithm?

    1. 17 = 5 x 1 + 12
    2. 17 = 5 x 3 + 2
    3. 17 = 5 x 4 - 3
    4. 17 = 5 x 5 - 8
  5. Among 20 people, 15 either swim or jog or both. If 5 swim and 6 swim and jog, how many jog?

    1. 6
    2. 16
    3. 24
    4. 46
  6. Let g be a function defined by g(x) = x + 1. Then the composition of (g o g)(x)is ______.

    1. x
    2. x + 1
    3. x + 2
    4. x2 + 2x + 1
  7. For the following relation to be a function, x can not be what values?
    R = {(2,4), (x,1), (4,2), (5,6)}

    1. x cannot be 2, 4 or 5
    2. x cannot be 4, 1 or 6
    3. x cannot be 2, 4 or 6
    4. x cannot be 1, 2 or 6
  8. The negation of “Today is Friday” is

    1. Today is Saturday
    2. Today is not Friday
    3. Today is Thursday
    4. None of the given
  9. Suppose there are 8 different tea flavors and 5 different biscuit brands. A guest wants to take one tea and one brand of biscuit. How many choices are there for this guest?

    1. 5
    2. 8
    3. 13
    4. 40
  10. Let R be the universal relation on a set A then which one of the following statement about R is true?

    1. R is not symmetric
    2. R is not reflexive
    3. R is not transitive
    4. R is reflexive, symmetric and transitive.
  11. If A and B are any two sets, then A − B = B − A

    1. True
    2. False
  12. If r is a positive real number, then the value of r in 3.r.r = −27r is ________.

    1. −9
    2. +9
    3. 0
    4. None of the given
  13. If X and Y are random variables, then E(aX) is equal to

    1. E(aX)
    2. aE(X)
    3. aX
    4. None of the given
  14. A Random variable is also called a _________.

    1. Chance Variable
    2. Constant
  15. If order matters and repetition is allowed, then which counting method should be used in order to select 'k' elements from a total of 'n' elements?

    1. K-Selection
    2. K-Sample
    3. K-combination
    4. K-Permuatation
  16. Let R be a relation on a set A. If R is reflexive then its compliment is ____________.

    1. Reflexive
    2. Irreflexive
    3. Symmetric
    4. Antisymmetric
  17. The functions 'f' and 'g' are inverse of each other if and only if their composition gives _______.

    1. constant function
    2. identity function
    3. bijective function
    4. injective function
  18. One-to-One correspondence means the condition of ______.

    1. one-One
    2. identity
    3. onto
    4. one-One and onto
  19. If p ↔ q is True, then ________.

    1. Only p is True.
    2. Only q is True.
    3. p and q both are True.
    4. None of the given.
  20. The switches in parallel act just like ________.

    1. NOT gate
    2. AND gate
    3. OR gate
    4. XOR gate
  21. The statement p → q is logically equivalent to ∼q → ∼p

    1. True
    2. False
  22. Let R be a relation on a set A. If R is symmetric then its compliment is __________.

    1. Reflexive
    2. Irreflexive
    3. Symmetric
    4. Antisymmetric
  23. Determine values of x and y, where (2x, x + y) = (8, 6).

    1. x = 3 and y = 5
    2. x = 4 and y = 2
    3. x = 6 and y = 12
    4. x = 4 and y = 12
  24. If p is false and q is false, then ∼p implies q is ________.

    1. True
    2. False
  25. How many possible outcomes are there when a fair coin is tossed four times?

    1. 4
    2. 8
    3. 16
    4. 32
  26. If X and Y are independent random variables, then E(XY) is equal to

    1. E(XY)
    2. XE(Y)
    3. YE(X)
    4. E(x)E(y)
  27. If p = It is raining, q = She will go to college
    "It is raining and she will not go to college”
    will be denoted by

    1. p ∧ ∼q
    2. p ∧ q
    3. ∼(p ∧ q)
    4. ∼p ∧ q
  28. Reductio and absurdum' is another name of _________.

    1. Direct Method of proof
    2. proof by contradiction
    3. proof by contapositive
    4. None of the given
  29. Which of the followings is the product set A * B * C ? where A = {a}, B = {b}, and C = {c, d}.

    1. {(a, b, c), (a, b, d)}
    2. {(a, c, b), (a, d, b)}
    3. {(b, c, a), (b, d, a)}
    4. {(c, b, a), (d, b, a)}
  30. The method of loop invariants is used to prove __________ of a loop with respect to certain pre and post-conditions.

    1. falseness
    2. correctness
  31. ∼(P → q) is logically equivalent to _________.

    1. p ∧ ∼q
    2. p ∨ ∼q
    3. ∼p ∧ q
    4. ∼p ∨ q
  32. The disjunction of p and q is written as ________.

    1. p ∨ q
    2. p ∧ q
    3. p XOR q
    4. None of the given
  33. The logical statement p ∧ q means ________.

    1. p OR q
    2. p NOT q
    3. p AND q
    4. p XOR q
  34. An integer n is a perfect square if and only if ________ for some integer k.

    1. n = 2k
    2. n = k^2
    3. n = square-root of k
    4. n = k^3
  35. In how many ways a student can choose a course from 2 science courses,3 literature courses and 5 art courses.

    1. 30
    2. 10
    3. 1440
    4. 240
  36. If X and Y are independent random variables and a and b are constants, then Var(aX + bY)is equal to

    1. aVar(X) + bVar(Y)
    2. (a + b)[Var(X) + Var(Y)]
    3. Var(aX) + Var(bY)
    4. a^2 Var(X) + b^2 Var(Y)
  37. If a function (g o f)(x):X→Z is defined as (g o f)(x) = g(f(x)) for all x ∈ X. Then the function ________ is known as composition of f and g.

    1. (f o g)
    2. f-1(g(x))
    3. (g o f)
    4. g-1(f(x))
  38. In how many ways can 6 people be seated on 6 available seats?

    1. 120
    2. 6
    3. 12
    4. 720
  39. The set Z of all integers is _____.

    1. uncountable
    2. countable
  40. Let X = {1, 2, 3}, then 2-combinations of the 3 elements of the set X are _________?

    1. {1, 2}, {1, 3} and {2, 3}
    2. {1, 2}, {2, 1}, {1, 3}, {3, 1}, {2, 3}, and {3, 2}
    3. {1, 2}, {2, 1}, {1, 3} and {2, 3}
    4. {1, 2}, {2, 1},{1, 3} and {3, 1}
  41. 'p is equivalent to q' means ________.

    1. p is not necessary but p is sufficient for q.
    2. p is neither necessary nor sufficient for q.
    3. p is necessary and sufficient for q.
    4. p is necessary but not sufficient for q.
  42. A set is called finite, if and only if, it is the ________ or there is ________ .

    1. empty set, onto
    2. empty set, one-to-one
    3. one-to-one, onto
    4. empty set, bijective
  43. Let p → q be a conditional statement, then the statement q → p is called ________.

    1. Inverse
    2. Converse
    3. Contrapositive
    4. Double conditional
  44. (-2)! = _________ ?

    1. -2
    2. 0
    3. 2
    4. Undefined
  45. A student can choose a computer project from one of the two lists. The two lists contain 12 and 18 possible projects, respectively. How many possible projects are there to choose from?

    1. 12
    2. 18
    3. 30
    4. 216
  46. Real valued function is a function that assigns _______ to each member of its domain.

    1. negative real number
    2. positive real number
    3. only a real number
    4. any arbitrary real number
  47. Let R be a relation on a set A. If R is reflexive then its compliment is ________ .

    1. Reflexive
    2. Irreflexive
    3. Symmetric
    4. Antisymmetric
  48. x belongs to A or x belongs to B, therefore x belongs to ________.

    1. A intersection B
    2. A union B
    3. A difference B
    4. A symmetric difference B
  49. Range of the relation {(0,1), (3,22), (90,34)} is __________ .

    1. {0, 3, 90}
    2. {1, 22, 34}
    3. {0, 1, 3}
    4. {0, 1, 3, 22, 90, 34}
  50. The number of the words that can be formed from the letters of the word,“COMMITTEE” are

    1. 9p9
    2. 9C9
    3. 9! / (2!2!2!)
    4. None of the given
  51. The contrapositive of the conditional statement 'If it is Sunday, then I go for shopping' is ________.

    1. I do Not go for shopping, then it is Not Sunday.
    2. I go for shopping, then it is Sunday.
    3. I do Not go for shopping, then it is Sunday.
    4. I go for shopping, then it is Not Sunday.
  52. Let f(x) = x2 + 1 define functions f from R to R and c = 2 be any scalar, then c.f(x) is ______.

    1. 2
    2. x2 + 1
    3. 2x2 - 1
    4. 2x2 + 2
  53. Let X = {2, 4, 5} and Y= {1, 2, 4} and R be a relation from X to Y defined by R = {(2,4), (4,1), (a,2)}. For what value of ‘a‘ the relation R is a function ?

    1. 1
    2. 2
    3. 4
    4. 5
  54. Let f(x)=3x and g(x) = 3x − 2 define functions f and g from R to R. Then (f+g)(x) = ________.

    1. −2
    2. 6x + 2
    3. 6x − 2
    4. 6x.x − 2
  55. The converse of the conditional statement p → q is

    1. q → p
    2. ∼q → ∼p
    3. ∼p → ∼q
    4. None of the given
  56. Which of the followings is the product set A * B * C ? where A = {a}, B = {b}, and C = {c, d}.

    1. {(a, b, c), (a, b, d)}
    2. {(a, c, b), (a, d, b)}
    3. {(b, c, a), (b, d, a)}
    4. {(c, b, a), (d, b, a)}
  57. If f and g are two one-to-one functions, then their composition that is gof is one-to-one.

    1. TRUE
    2. FALSE
  58. There are three bus lines between A and B, and two bus lines between B and C. Find the number of ways a person can travel round trip by bus from A to C by way of B?

    1. 5
    2. 6
    3. 10
    4. 36
  59. Find the number of distinct permutations that can be formed using the letters of the word ”BENZENE”

    1. 120
    2. 220
    3. 320
    4. 420
  60. The conjunction p ∧ q is True when _________.

    1. p is True, q is False
    2. p is False, q is True
    3. p is True, q is True
    4. p is False, q is False
  61. P(0, 0)=______?

    1. 0
    2. 1
    3. 2
    4. undefined
  62. Let f(x) = 3x and g(x) = x + 2 define functions f and g from R to R, then (f.g)(x) is _____.

    1. 2x − 2
    2. 3x + 2
    3. 4x + 2
    4. 3x2 + 6x
  63. Let p be True and q be True, then ( ∼p ∧ q ) is ________.

    1. t ( where t is tautology. )
    2. c ( where c is contradiction. )
    3. True
    4. False
  64. The total number of terms in an arithmetic series 0 + 5 + 10 + 15 + .... + 50 are ________.

    1. 9
    2. 10
    3. 11
    4. infinite
  65. Let A = {1, 2, 3, 4} and B = {7} then the constant function from A to B is _________ .

    1. Onto
    2. One to one
    3. Both one to one and onto
    4. Neither one to one nor onto
  66. Which relations below are functions?
    R1 = {(3,4), (4,5), (6,7), (8,9)}
    R2 = {(3,4), (4,5), (6,7), (3,9)}
    R3 = {(-3,4), (4,-5), (0,0), (8,9)}
    R4 = {(8,11), (34,5), (6,17), (8,19)}

    1. R1 and R3 are functions
    2. R1 and R2 are functions
    3. R2 and R4 are functions
    4. R3 and R2 are functions
  67. What is the truth value of the sentence?
    'It rains if and only if there are clouds.'

    1. True
    2. False
  68. Let p1, p2, p3 be True premises in a given Truth Table. If the conjunctions of the Conclusion with each of p1, p2, p3 are True, then the argument is ________.

    1. False
    2. True
    3. Invalid
    4. Valid
  69. The set of prime numbers is _________.

    1. finite set
    2. infinite set
    3. continuous set
    4. None of the given
  70. If A and B are disjoint finite sets then n(A ∪ B) = ______.

    1. n(A) − n(B)
    2. n(A) + n(B) − n(A ∩ B)
    3. n(A) + n(B)
    4. n(A) + n(B) + n(A ∩ B)
  71. The disjunction p ∨ q is False when ________.

    1. p is False, q is True.
    2. p is True, q is False.
    3. p is True, q is True.
    4. p is False, q is False.
  72. Let A = {1, 2, 3} and B = {2, 4} then number of functions from A to B are _________.

    1. 6
    2. 8
    3. 16
    4. 64
  73. A non-zero integer d divides an integer n if and only if there exists an integer k such that _________.

    1. n = d / k
    2. n = d k
    3. n = d + k
    4. n = d - k
  74. The converse of the conditional statement 'If I live in Quetta, then I live in Pakistan' is ________.

    1. If I live in Pakistan, then I live in Quetta.
    2. If I live in Pakistan, then I do Not live in Quetta.
    3. If I do Not live in Quetta, then I do Not live in Pakistan
    4. If I do Not live in Quetta, then I live in Pakistan
  75. Which of the followings is the factorial form of 5 . 4?

    1. 5/3
    2. 5!/3
    3. 5!/3!
    4. 5/3!
  76. A predicate becomes _________ when its variables are given specific values.

    1. sentence
    2. statement
    3. algorithm
    4. iteration
  77. If A and B be events with P(A) = 1/3, P(B) = 1/4 and P(A ∩ B) = 1/6, then P(A ∪ B) = ________ .

    1. 2/3
    2. 5/12
    3. 1/24
    4. 1/2
  78. R = {(a,1), (b,2), (c,3), (d,4)} then the inverse of this relation is _______.

    1. {(a,1), (b,2), (3,c), (4,d)}
    2. {(1,a), (2,b), (3,c), (4,d)}
    3. {(a,1), (2,b), (3,c), (4,d)}
    4. {(1,a), (b,2), (3,c), (4,d)}
  79. If A = Set of students of virtual university then A has been written in the _________.

    1. Tabular form
    2. Set builder form
    3. Descriptive form
    4. A is not a set
  80. A box contains 5 different colored light bulbs. Which of the followings is the number of ordered samples of size 3 with replacement?

    1. 8
    2. 15
    3. 125
    4. 243
  81. In how many ways a student can choose one of each of the courses when he is offered 3 mathematics courses, 4 literature courses and 2 history courses.

    1. 9
    2. 24
    3. 288
    4. 14
  82. Let A and B be subsets of U with n(A) = 12, n(B) = 15, n(A') = 17, and n(A intersection B) = 8, then n(U)=______ .

    1. 27
    2. 29
    3. 20
    4. 35
  83. There are 5 girls students and 20 boys students in a class. How many students are there in total ?

    1. 4
    2. 15
    3. 25
    4. 100
  84. What is the minimum number of students in a class to be sure that two of them are born in the same month?

    1. 11
    2. 12
    3. 13
    4. 14
  85. A student is to answer five out of nine questions on exams. Find the number of ways that can choose the five questions.

    1. 216
    2. 316
    3. 126
    4. None of the given
  86. If p is false and q is true, then ∼p ↔ q is ________.

    1. True
    2. False
  87. The functions f o g and g o f are always equal.

    1. TRUE
    2. FALSE
  88. Let A = {2, 3, 5, 7}, B = {2, 3, 5, 7, 2}, C = Set of first five prime numbers. Then from the following which statement is true ?

    1. A = B
    2. A = C
    3. B = C
    4. All the three sets are equal.