This set of Discrete Mathematics Multiple Choice Questions & Answers (MCQs) focuses on “Set Operations”.

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}

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Explanation: The union of the sets A and B, is the set that contains those elements that are either in A or in B.

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}

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Explanation: The intersection of the sets A and B, is the set containing those elements that are in both A and B.

3. Two sets are called disjoint if there _____________ is the empty set.

a) Union

b) Difference

c) Intersection

d) Complement

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Explanation: By the definition of the disjoint set.

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}

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Explanation: Two sets are disjoint if the intersection of two sets is the empty set.

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

a) {1}

b) {5}

c) {3}

d) {2}

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Explanation: The difference of the sets A and B denoted by A-B, is the set containing those elements that are in A not in B.

6. The complement of the set A is _____________

a) A – B

b) U – A

c) A – U

d) B – A

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Explanation: The complement of the set A is the complement of A with respect to U.

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

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Explanation: The bit string for the set has a one bit in second, fourth, sixth, eighth, tenth positions, and a zero elsewhere.

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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Explanation: By the definition of the generalized intersection of the set.

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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Explanation: The bit string for the union is the bitwise OR of the bit strings.

10. The set difference of the set A with null set is __________

a) A

b) null

c) U

d) B

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Explanation: The set difference of the set A by null set denoted by A – {null} is A.

**Sanfoundry Global Education & Learning Series – Discrete Mathematics**

To practice all areas of Discrete Mathematics, __here is complete set of 1000+ Multiple Choice Questions and Answers__.