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

Discrete Mathematics (MTH202)

Multiple Choice Questions (MCQs)

Objective Questions

  1. 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
  2. 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
  3. 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
  4. 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
  5. 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
  6. 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.
  7. 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
  8. The converse of the conditional statement p → q is

    1. q → p
    2. ∼q → ∼p
    3. ∼p → ∼q
    4. None of the given
  9. 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
  10. The switches in parallel act just like ________.

    1. NOT gate
    2. AND gate
    3. OR gate
    4. XOR gate
  11. 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
  12. A tree is normally constructed from ________.

    1. right
    2. center
    3. left to right
    4. right to left
  13. 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))
  14. 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
  15. 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
  16. If p is false and q is false, then ∼p implies q is ________.

    1. True
    2. False
  17. 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
  18. 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
  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. 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}
  21. 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
  22. In how many ways can 6 people be seated on 6 available seats?

    1. 120
    2. 6
    3. 12
    4. 720
  23. The functions f o g and g o f are always equal.

    1. TRUE
    2. FALSE
  24. 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
  25. If f and g are two one-to-one functions, then their composition that is gof is one-to-one.

    1. TRUE
    2. FALSE
  26. The set Z of all integers is _____.

    1. uncountable
    2. countable
  27. 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
  28. The total number of terms in an arithmetic series 0 + 5 + 10 + 15 + .... + 50 are ________.

    1. 9
    2. 10
    3. 11
    4. infinite
  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. 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
  31. 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)
  32. 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
  33. How many possible outcomes are there when a fair coin is tossed four times?

    1. 4
    2. 8
    3. 16
    4. 32
  34. 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
  35. 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
  36. 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
  37. 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
  38. 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
  39. 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
  40. 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
  41. 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
  42. A predicate becomes _________ when its variables are given specific values.

    1. sentence
    2. statement
    3. algorithm
    4. iteration
  43. If p is false and q is true, then ∼p ↔ q is ________.

    1. True
    2. False
  44. 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
  45. 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.
  46. The disjunction of p and q is written as ________.

    1. p ∨ q
    2. p ∧ q
    3. p XOR q
    4. None of the given
  47. 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)
  48. 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
  49. 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
  50. A Random variable is also called a _________.

    1. Chance Variable
    2. Constant
  51. The logical statement p ∧ q means ________.

    1. p OR q
    2. p NOT q
    3. p AND q
    4. p XOR q
  52. 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.
  53. 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)}
  54. If A and B are any two sets, then A − B = B − A

    1. True
    2. False
  55. The set of prime numbers is _________.

    1. finite set
    2. infinite set
    3. continuous set
    4. None of the given
  56. '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.
  57. 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
  58. The statement p → q is logically equivalent to ∼q → ∼p

    1. True
    2. False
  59. 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
  60. 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}
  61. 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.
  62. Let p → q be a conditional statement, then the statement q → p is called ________.

    1. Inverse
    2. Converse
    3. Contrapositive
    4. Double conditional
  63. 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
  64. ( p ∨ ∼p ) is the ________.

    1. Contradiction
    2. Conjunction
    3. Tautology
    4. Contingency
  65. 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
  66. 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
  67. Which of the followings is the factorial form of 5 . 4?

    1. 5/3
    2. 5!/3
    3. 5!/3!
    4. 5/3!
  68. 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
  69. 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)
  70. 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)}
  71. 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
  72. 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
  73. 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
  74. One-to-One correspondence means the condition of ______.

    1. one-One
    2. identity
    3. onto
    4. one-One and onto
  75. 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
  76. 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
  77. (-2)! = _________ ?

    1. -2
    2. 0
    3. 2
    4. Undefined
  78. ∼(P → q) is logically equivalent to _________.

    1. p ∧ ∼q
    2. p ∨ ∼q
    3. ∼p ∧ q
    4. ∼p ∨ q
  79. 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
  80. 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
  81. 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
  82. 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
  83. What is the truth value of the sentence?
    'It rains if and only if there are clouds.'

    1. True
    2. False
  84. The method of loop invariants is used to prove __________ of a loop with respect to certain pre and post-conditions.

    1. falseness
    2. correctness
  85. 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
  86. 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
  87. P(0, 0)=______?

    1. 0
    2. 1
    3. 2
    4. undefined
  88. 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