Set Operations 1

**1. The union of the sets {1, 2, 5} and {1, 2, 6} is the set _______________**a) {1, 2, 6, 1}

**b) {1, 2, 5, 6}**

c) {1, 2, 1, 2}

d) {1, 5, 6, 3}

**2. The intersection of the sets {1, 2, 5} and {1, 2, 6} is the set _____________a) {1, 2}**b) {5, 6}

c) {2, 5}

d) {1, 6}

**3. Two sets are called disjoint if there _____________ is the empty set.**a) Union

b) Difference

**c) Intersection**

d) Complement

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**4. Which of the following two sets are disjoint?**a) {1, 3, 5} and {1, 3, 6}

b) {1, 2, 3} and {1, 2, 3}

c) {1, 3, 5} and {2, 3, 4}

**d) {1, 3, 5} and {2, 4, 6}**

**5. The difference of {1, 2, 3} and {1, 2, 5} is the set ____________**a) {1}

b) {5}

**c) {3}**

d) {2}

**6. The complement of the set A is _____________**a) A – B

**b) U – A**

c) A – U

d) B – A

**7. The bit string for the set {2, 4, 6, 8, 10} (with universal set of natural numbers less than or equal to 10) is ____________________a) 0101010101**b) 1010101010

c) 1010010101

d) 0010010101

**8. Let Ai = {i, i+1, i+2, …..}. Then set {n, n+1, n+2, n+3, …..} is the _________ of the set Ai.**a) Union

**b) Intersection**

c) Set Difference

d) Disjoint

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**9. The bit strings for the sets are 1111100000 and 1010101010. The union of these sets is ___________**

a) 1010100000

b) 1010101101

c) 1111111100**d) 1111101010**

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**10. The set difference of the set A with null set is __________a) A**b) null

c) U

d) B

__Set Operations – 2__

**1. Let the set A is {1, 2, 3} and B is {2, 3, 4}. Then the number of elements in A U B is?a) 4**b) 5

c) 6

d) 7

Explanation: AUB is {1, 2, 3, 4}.

**2. Let the set A is {1, 2, 3} and B is { 2, 3, 4}. Then number of elements in A ∩ B is?**a) 1

**b) 2**

c) 3

d) 4

**3. Let the set A is {1, 2, 3} and B is {2, 3, 4}. Then the set A – B is? **a) {1, -4}

b) {1, 2, 3}

**c) {1}**

d) {2, 3}

Explanation: In A – B the common elements get cancelled.

**4. In which of the following sets A – B is equal to B – A?**a) A = {1, 2, 3}, B = {2, 3, 4}

b) A = {1, 2, 3}, B = {1, 2, 3, 4}

**c) A = {1, 2, 3}, B = {2, 3, 1}**

d) A = {1, 2, 3, 4, 5, 6}, B = {2, 3, 4, 5, 1}

**5. Let A be set of all prime numbers, B be the set of all even prime numbers, C be the set of all odd prime numbers, then which of the following is true?**a) A ≡ B U C

b) B is a singleton set.

c) A ≡ C U {2}

**d) All of the mentioned**

**6. If A has 4 elements B has 8 elements then the minimum and maximum number of elements in A U B are ____________**a) 4, 8

**b) 8, 12**

c) 4, 12

d) None of the mentioned

**7. If A is {{Φ}, {Φ, {Φ}}}, then the power set of A has how many element?**a) 2

**b) 4**

c) 6

d) 8

**8. Two sets A and B contains a and b elements respectively. If power set of A contains 16 more elements than that of B, value of ‘b’ and ‘a’ are _______a) 4, 5**b) 6, 7

c) 2, 3

d) None of the mentioned

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**9. Let A be {1, 2, 3, 4}, U be set of all natural numbers, then U-A’(complement of A) is given by set.**a) {1, 2, 3, 4, 5, 6, ….}

b) {5, 6, 7, 8, 9, ……}

**c) {1, 2, 3, 4}**

d) All of the mentioned

Explanation: U – A’ ≡ A.**10. Which sets are not empty?**a) {x: x is a even prime greater than 3}

b) {x : x is a multiple of 2 and is odd}

c) {x: x is an even number and x+3 is even}

**d) { x: x is a prime number less than 5 and is odd}**