Discrete Mathematics (MTH202)

1. 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

2. 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

3. 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

4. The switches in parallel act just like ________.

   1. NOT gate
   2. AND gate
   3. OR gate
   4. XOR gate

5. The method of loop invariants is used to prove __________ of a loop with respect to certain pre and post-conditions.

   1. falseness
   2. correctness

6. 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

7. If f and g are two one-to-one functions, then their composition that is gof is one-to-one.

   1. TRUE
   2. FALSE

8. 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

9. 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

10. 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

11. The set of prime numbers is _________.

    1. finite set
    2. infinite set
    3. continuous set
    4. None of the given

12. 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

13. 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)}

14. 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

15. P(0, 0)=______?

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

16. '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.

17. A Random variable is also called a _________.

    1. Chance Variable
    2. Constant

18. 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

19. 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

20. 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

21. 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

22. How many possible outcomes are there when a fair coin is tossed four times?

    1. 4
    2. 8
    3. 16
    4. 32

23. 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

24. 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

25. 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

26. The disjunction of p and q is written as ________.

    1. p ∨ q
    2. p ∧ q
    3. p XOR q
    4. None of the given

27. ∼(P → q) is logically equivalent to _________.

    1. p ∧ ∼q
    2. p ∨ ∼q
    3. ∼p ∧ q
    4. ∼p ∨ q

28. 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

29. 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

30. 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)

31. The functions f o g and g o f are always equal.

    1. TRUE
    2. FALSE

32. The set Z of all integers is _____.

    1. uncountable
    2. countable

33. 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)

34. 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

35. 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

36. ( p ∨ ∼p ) is the ________.

    1. Contradiction
    2. Conjunction
    3. Tautology
    4. Contingency

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. 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}

39. 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

40. 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

41. 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

42. 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

43. 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}

44. (-2)! = _________ ?

    1. -2
    2. 0
    3. 2
    4. Undefined

45. Which of the followings is the factorial form of 5 . 4?

    1. 5/3
    2. 5!/3
    3. 5!/3!
    4. 5/3!

46. 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.

47. If p is false and q is false, then ∼p implies q is ________.

    1. True
    2. False

48. What is the truth value of the sentence?
    'It rains if and only if there are clouds.'

    1. True
    2. False

49. The converse of the conditional statement p → q is

    1. q → p
    2. ∼q → ∼p
    3. ∼p → ∼q
    4. None of the given

50. 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

51. 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

52. 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

53. If p is false and q is true, then ∼p ↔ q is ________.

    1. True
    2. False

54. A tree is normally constructed from ________.

    1. right
    2. center
    3. left to right
    4. right to left

55. 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

56. 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

57. 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

58. One-to-One correspondence means the condition of ______.

    1. one-One
    2. identity
    3. onto
    4. one-One and onto

59. The logical statement p ∧ q means ________.

    1. p OR q
    2. p NOT q
    3. p AND q
    4. p XOR q

60. 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

61. The total number of terms in an arithmetic series 0 + 5 + 10 + 15 + .... + 50 are ________.

    1. 9
    2. 10
    3. 11
    4. infinite

62. 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

63. 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

64. 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

65. 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)

66. 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

67. 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)}

68. 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

69. 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

70. 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.

71. A predicate becomes _________ when its variables are given specific values.

    1. sentence
    2. statement
    3. algorithm
    4. iteration

72. 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

73. The statement p → q is logically equivalent to ∼q → ∼p

    1. True
    2. False

74. 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.

75. 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

76. 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

77. 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.

78. 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

79. 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

80. 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

81. 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)}

82. Let p → q be a conditional statement, then the statement q → p is called ________.

    1. Inverse
    2. Converse
    3. Contrapositive
    4. Double conditional

83. In how many ways can 6 people be seated on 6 available seats?

    1. 120
    2. 6
    3. 12
    4. 720

84. 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

85. 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

86. 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.

87. If A and B are any two sets, then A − B = B − A

    1. True
    2. False

88. 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

Select a course code for Objective Questions:

ACC311 ACC501 BIF101 BIF401 BIF501 BIO101 BIO201 BIO202 BIO203 BIO204 BIO301 BIO302 BIO303 BIO401 BIO503 BNK603 BT101 BT201 BT301 BT302 BT401 BT402 BT403 BT404 BT405 BT406 BT501 BT504 BT505 BT604 CHE201 CHE301 CS001 CS101 CS201 CS202 CS204 CS301 CS302 CS304 CS311 CS401 CS402 CS403 CS408 CS501 CS502 CS504 CS506 CS508 CS601 CS602 CS604 CS605 CS607 CS609 CS610 CS614 CS707 CS710 ECO401 ECO402 ECO403 ECO404 EDU302 EDU401 EDU402 EDU501 EDU601 ENG101 ENG201 ENG301 ENG501 FIN611 FIN624 FIN625 ISL201 IT430 MCM101 MCM301 MGMT623 MGT101 MGT211 MGT301 MGT401 MGT402 MGT501 MGT502 MGT503 MGT510 MGT601 MGT603 MKT501 MKT610 MKT630 MTH101 MTH202 MTH302 MTH501 MTH601 MTH634 PAK301 PHY101 PHY301 PSY101 PSY403 PSY502 PSY512 SOC101 SOC301 SOC401 STA301 STA630 STA641 ZOO102 ZOO401 ZOO501 ZOO502 ZOO503 ZOO504 ZOO505 ZOO506 ZOO510 ZOO630

Select a course code for Subjective Questions:

ACC311 CS001 CS101 CS201 CS301 CS607 CS701 CS702 CS703 CS704 CS707 CS708 CS710 CS711 CS718 CS721 CS724 ECO401 ECO403 ENG101 ENG301 MGT703 MTH501 STA301