Q61. A, B, C are sub-sets of the universal set S and if A ∪ ∪ ∪ B = A ∪ ∪ ∪ C and A'∪ ∪ ∪ B = A' ∪ ∪ ∪ C then -
A B = C
B A = B
C B' = C
D A' = B
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Correct answer: B = C
Q62. A relation ρ is defined on a set N by "aρb if and only if a is divisible by b" for all a, b ∈ N. Then ρ is -
A Reflexive and transitive
B Reflexive and systematic
C Equivalence
D Systematic and transitive
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Correct answer: Reflexive and transitive
Q63. Let f: A → → → B and g: B → → → C be both injective mapping such that gof: A → → → C is injective, then
A g is injective but f need not be
B f is injective but g need not be
C both f and g are injective
D both f and g are not injective
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Correct answer: Discrepancy / answer not specified in source
Q64. The function f: R → → 1 1 –,, 2 2 defined as f(x) = 2 x 1+ x, is -
A Surjective but not injective
B Injective but not surjective
C Neither injective nor surjective
D Invertible
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Correct answer: Invertible
Q65. If A, B, C, are three sets, then the Set A – (B – C) is equal to
A (A–B)∪(A∩C)
B (A–B)∩C
C (A–B)∩(B–C)
D A ∩ (B–C)
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Correct answer: (A–B)∪(A∩C)
Q66. The function f: [0, 3] → → → [1, 29] defined by f(x) = 2x3 - 15x2 + 36x + 1, is
A One-one but not onto
B One-one and onto
C Onto but not One-one
D Neither One-one nor onto
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Correct answer: Onto but not One-one
Q67. Let A be a set of n elements and B be a set of m elements, then the total number of mapping from A to B is
A nm
B mn
C n/Cm
D mn
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Correct answer: mn
Q68. Let A be a set of 4 elements and B be a set of 3 elements, then the total number of surjective mappings from A to B is
A 36
B 12
C 72
D 144
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Correct answer: 36
Q69. If f: R → → → R be defined by f(x) = x2, x∈R then f is
A Bijective
B Injective
C Surjective
D Not Bijective
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Correct answer: Not Bijective
Q70. If f: A → → → B be a mapping and P ⊂ ⊂ ⊂ A, then which of the following is true?
A ff–1(P) ⊂ P ff–1(P) = P if f is injective
B ff–1(P) = P if f is injective
C f–1(Pc/)⊂[f–1(P)]c
D [f(P)c ⊂ f(Pc)]
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Correct answer: Discrepancy / answer not specified in source
Q71. Which one of the following in not a convex set?
A X = {(x, y): x ≥ 3, y ≤ 5}
B X = {(x, y): x2 + y2 < 9}
C X = {(x, y): 4 ≤ x2 + y2 ≤ 9}
D X = {(x, y): x2 + y2 ≤ 9}
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Correct answer: X = {(x, y): 4 ≤ x2 + y2 ≤ 9}
Q72. If f: ℝ ℝ ℝ → ℝ ℝ ℝ, g: ℝ ℝ ℝ → ℝ ℝ ℝ are defined by f(x) = 4x – 1 and g(x) = x2 + 2, then fof(x) =
A 16x – 5
B 27
C a2/+ 2
D 16x2/– 8x + 3
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Correct answer: 16x – 5
Q73. A set S has 3 elements. The number of elements in power set of S is
A 64
B 8
C 24
D 256
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Correct answer: 8
Q74. If A and B are countable sets, then A × B is
A Uncountable
B Infinite
C Finite
D Countable
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Correct answer: Countable
Q75. In a class of 60 students, 30 students passed in Mathematics and 40 passed in Science. At least how many students passed in both Mathematics and Science?
A 10
B 9
C 11
D 0
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Correct answer: 10
Q76. The domain of 2 x x f(x) 2sin((1 x)) e 2 is:
A x > 1
B R
C R – {0}
D –1 ≤ x ≤ 1
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Correct answer: –1 ≤ x ≤ 1
Q77. If 1 f(x) 1, x then the value of 1 f f x is:
A x/x 1
B x
C x 2/x 1
D x/x 1
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Correct answer: x 2/x 1
Q78. Let E ⊆ ⊆ ⊆ℝ and f, g, h are the functions from E into ℝ. Suppose a ∈ E and f, g, h are continuous at 'a', then for h(
A bijection
B not continuous at a
C surjection
D continuous at a
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Correct answer: continuous at a
Q79. For two different finite sets A and B, Inclusion- Exclusion relation states that:
A n(AUB) n(A) n(B) n(A B) ∩
B n(AUB) n(A) n(B) n(A B) ∩
C n(AUB) n(A) n(B) n(A B) ∩
D n(AUB) n(A) n(B) n(A B) ∩
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Correct answer: n(AUB) n(A) n(B) n(A B) ∩
Q80. A B B – A _____. + = ∩
A B
B A
C AUB
D φ
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Correct answer: B