Quiznetik

Discrete Mathematics | Set 3

1. If in sets A, B, C, the set B ∩ C consists of 8 elements, set A ∩ B consists of 7 elements and set C ∩ A consists of 7 elements then the minimum element in set A U B U C will be?

Correct : A. 8

2. Let (A7, ⊗7)=({1, 2, 3, 4, 5, 6}, ⊗7) is a group. It has two sub groups X and Y. X={1, 3, 6}, Y={2, 3, 5}. What is the order of union of subgroups?

Correct : B. 5

3. A relation (34 × 78) × 57 = 57 × (78 × 34) can have                      property.

Correct : B. associative

4. B1: ({0, 1, 2….(n-1)}, xm) where xn stands for “multiplication-modulo-n” and B2: ({0, 1, 2….n}, xn) where xn stands for “multiplication-modulo-m” are the two statements. Both B1 and B2 are considered to be

Correct : B. semigroups

5. If group G has 65 elements and it has two subgroups namely K and L with order 14 and 30. What can be order of K intersection L?

Correct : C. 5

6. Consider the binary operations on X, a*b = a+b+4, for a, b ∈ X. It satisfies the properties of

Correct : A. abelian group

7. Let * be the binary operation on the rational number given by a*b=a+b+ab. Which of the following property does not exist for the group?

Correct : B. identity property

8. A group G, ({0}, +) under addition operation satisfies which of the following properties?

Correct : B. closure, associativity, inverse and identity

9. If (M, *) is a cyclic group of order 73, then number of generator of G is equal to

Correct : C. 72

10. The set of even natural numbers, {6, 8, 10, 12,..,} is closed under addition operation. Which of the following properties will it satisfy?

Correct : A. closure property

11. A non empty set A is termed as an algebraic structure

Correct : A. with respect to binary operation *

12. An algebraic structure                    is called a semigroup.

Correct : A. (p, *)

13. Condition for monoid is

Correct : D. (a*e)=(e*a)=a

14. A monoid is called a group if

Correct : D. (a*c)=(c*a)=e

15. Matrix multiplication is a/an                     property.

Correct : B. associative

16. How many properties can be held by a group?

Correct : C. 5

17. A cyclic group is always

Correct : A. abelian group

18. {1, i, -i, -1} is

Correct : C. a trivial group

19. Let K be a group with 8 elements. Let H be a subgroup of K and H<K. It is known that the size of H is at least 3. The size of H is

Correct : C. cyclic group

20. is not necessarily a property of a Group.

Correct : A. commutativity

21. A group of rational numbers is an example of

Correct : B. a subgroup of a group of real numbers

22. Intersection of subgroups is a

Correct : B. subgroup

23. What is a circle group?

Correct : A. a subgroup complex numbers having magnitude 1 of the group of nonzero complex elements

24. A normal subgroup is

Correct : D. an invariant equipped with conjugation by the elements of original group

25. Two groups are isomorphic if and only if                      is existed between them.

Correct : C. isomorphism

26. a * H is a set of            coset.

Correct : B. left

27. a * H = H * a relation holds if

Correct : D. h is subgroup of an abelian group

28. Lagrange’s theorem specifies

Correct : B. the order of the subgroup divides the order of the finite group

29. A function is defined by f(x)=2x and f(x + y) = f(x) + f(y) is called

Correct : A. isomorphic

30. An isomorphism of a group onto itself is called

Correct : D. automorphism

31. The elements of a vector space form a/an                          under vector addition.

Correct : A. abelian group

32. A set of representatives of all the cosets is called

Correct : D. transversal

33. Which of the following statement is true?

Correct : C. the set of all non-singular matrices forms a group under multiplication

34. How many different non-isomorphic Abelian groups of order 8 are there?

Correct : C. 2

35. Consider the set B* of all strings over the alphabet set B = {0, 1} with the concatenation operator for strings

Correct : A. does not form a group

36. All groups satisfy properties

Correct : B. g-i to g-iv

37. An Abelian Group satisfies the properties

Correct : A. g-i to g-v

38. A Ring satisfies the properties

Correct : D. g-i to r-iii

39. A Ring is said to be commutative if it also satisfies the property

Correct : D. r-iv

40. An ‘Integral Domain’ satisfies the properties

Correct : C. g-i to r-vi

41. a.(b.c) = (a.b).c is the representation for which property?

Correct : A. g-ii

42. a(b+c) = ac+bc is the representation for which property?

Correct : D. r-iii

43. For the group Sn of all permutations of n distinct symbols, what is the number of elements in Sn?

Correct : D. n!

44. Does the set of residue classes (mod 3) form a group with respect to modular addition?

Correct : A. yes

45. Does the set of residue classes (mod 3) form a group with respect to modular addition?

Correct : B. no

46. The less-than relation, <, on a set of real numbers is

Correct : A. not a partial ordering because it is not asymmetric and irreflexive equals antisymmetric

47. If the longest chain in a partial order is of length l, then the partial order can be written as            disjoint antichains.

Correct : C. l

48. Suppose X = {a, b, c, d} and π1 is the partition of X, π1 = {{a, b, c}, d}. The number of ordered pairs of the equivalence relations induced by

Correct : B. 10

49. The inclusion of              sets into R = {{1, 2}, {1, 2, 3}, {1, 3, 5}, {1, 2, 4}, {1, 2, 3, 4, 5}} is necessary and sufficient to make R a complete lattice under the partial order defined by set containment.

Correct : C. {1}

50. Consider the set N* of finite sequences of natural numbers with a denoting that sequence a is a prefix of sequence b. Then, which of the following is true?

Correct : A. every non-empty subset of has a greatest lower bound

51. A partial order ≤ is defined on the set S = {x, b1, b2, … bn, y} as x ≤ bi for all i and bi ≤ y for all i, where n ≥ 1. The number of total orders on the set S which contain the partial order ≤ is

Correct : C. n!

52. A Poset in which every pair of elements has both a least upper bound and a greatest lower bound is termed as

Correct : B. lattice

53. If every two elements of a poset are comparable then the poset is called

Correct : B. totally ordered poset

54. A                  has a greatest element and a least element which satisfy 0<=a<=1 for every a in the lattice(say, L).

Correct : D. bounded lattice

55. The graph given below is an example of

Correct : A. non-lattice poset

56. A sublattice(say, S) of a lattice(say, L) is a convex sublattice of L if

Correct : C. x<=y<=z, where x, y in s implies z in s, for every element x, y, z in l

57. The graph is the smallest non-modular lattice N5. A lattice is                if and only if it does not have a                isomorphic to N5.

Correct : D. modular, sublattice

58. Every poset that is a complete semilattice must always be a

Correct : B. complete lattice

59. A free semilattice has the                 property.

Correct : D. universal

60. Algebra of logic is termed as

Correct : C. arithmetic logic

61. What is the definition of Boolean functions?

Correct : B. a special mathematical function with n degrees such that f:yn–>y

62. F(X,Y,Z,M) = X`Y`Z`M`. The degree of the function is

Correct : C. 4

63. Which of the following is a Simplification law?

Correct : A. m.(~m+n) = m.n

64. What are the canonical forms of Boolean Expressions?

Correct : D. som and pom

65. Which of the following is/are the universal logic gates?

Correct : C. nand and nor

66. The logic gate that provides high output for same inputs

Correct : B. x-nor

67. The                        of all the variables in direct or complemented from is a maxterm.

Correct : A. addition

68. What is the use of Boolean identities?

Correct : A. minimizing the boolean expression

69. Inversion of single bit input to a single bit output using

Correct : A. not gate

70. There are                    numbers of Boolean functions of degree n.

Correct : B. 2(2*n)

71. A                    is a Boolean variable.

Correct : A. literal

72. Minimization of function F(A,B,C) = A*B*(B+C) is

Correct : D. ab

73. The set for which the Boolean function is functionally complete is

Correct : B. {., +, -}

74. (X+Y`)(X+Z) can be represented by

Correct : A. (x+y`z)

75. is a disjunctive normal form.

Correct : C. sum-of-products

76. a ⊕ b =

Correct : A. (a+b)(a`+b`)

77. Find the simplified expression A’BC’+AC’.

Correct : C. (a+b)c’

78. Evaluate the expression: (X + Z)(X + XZ’) + XY + Y.

Correct : D. x+y

79. Simplify the expression: A’(A + BC) + (AC + B’C).

Correct : D. ac

80. What is the simplification value of MN(M + N’) + M(N + N’)?

Correct : B. mn+m’n’ c) (1+m)

81. Simplify the expression XZ’ + (Y + Y’Z) + XY. TOPIC 5.5 MINIMIZATION OF BOOLEAN ALGEBRA

Correct : C. (x + y +z)

82. Find the simplified term Y’ (X’ + Y’) (X + X’Y)?

Correct : A. xy’

83. If an expression is given that x+x’y’z=x+y’z, find the minimal expression of the function F(x,y,z) = x+x’y’z+yz?

Correct : C. x + z

84. Simplify the expression: XY’ + X’ + Y’X’.

Correct : C. (xy)’

85. Minimize the Boolean expression using Boolean identities: A′B+ABC′+BC’+AB′C′.

Correct : A. b(ac)’ + ac’

86. Minimize the following Boolean expression using Boolean identities. F(A,B,C) = (A+BC’)(AB’+C)

Correct : D. a(b’ + c)

87. Which of the following statement is a proposition?

Correct : D. The only odd prime number is 2

88. The truth value of ‘4+3=7 or 5 is not prime’.

Correct : B. True

89. Which of the following option is true?

Correct : A. If the Sun is a planet, elephants will fly

90. What is the value of x after this statement, assuming the initial value of x is 5? ‘If x equals to one then x=x+2 else x=0’.

Correct : C. 0

91. Let P: I am in Bangalore.; Q: I love cricket.; then q -> p(q implies p) is?

Correct : A. If I love cricket then I am in Bangalore

92. Let P: If Sahil bowls, Saurabh hits a century.; Q: If Raju bowls, Sahil gets out on first ball. Now if P is true and Q is false then which of the following can be true?

Correct : C. Sahil bowled and Saurabh hits a century

93. The truth value ‘9 is prime then 3 is even’.

Correct : B. TTru

94. Let P: We should be honest., Q: We should be dedicated., R: We should be overconfident. Then ‘We should be honest or dedicated but not overconfident.’ Is best represented by?

Correct : D. P V Q ∧ ~R

95. If there are n distinct components in a statement then there are _______ combinations of values in the truth table.

Correct : A. 2^n

96. If P then Q is called _________ statement

Correct : C. conditional

97. (P->Q)-> (^Q) is __________.

Correct : A. not a well formed formula

98. A relation R in a set X is symmetric if ________.

Correct : C. xRy=>yRx

99. If a relation is reflexive, then all the diagonal entries in the relation matrix must be________.

Correct : B. 1

100. If R is reflexive, symmetric and transitive then the relation is said to be ________.

Correct : C. Equivalence relation