This set of Discrete Mathematics Questions and Answers for Aptitude test focuses on “Cardinality of Sets”.

1. The cardinality of the set A = {1, 2, 3, 4, 6} is?

a) 5

b) 6

c) Integer

d) None of the mentioned

View Answer

Explanation: 5, it is a number of elements in the sets.

2. For two equal sets there ___________

a) Cardinality is same

b) Cardinality is different

c) May be same or different

d) None of the mentioned

View Answer

Explanation: Two equal sets should have the same number of elements.

3. If A is a subset of B then _______

a) The cardinality of A is greater than B

b) The cardinality of B is greater than A

c) Can’t say

d) None of the mentioned

View Answer

Explanation: B contains all the elements of A, as well as other elements.

4. If there is a bijection between two sets A and B then _______

a) Cardinality of A is greater than B

b) Cardinality of B is greater than A

c) Cardinality of B is equal to A

d) None of the mentioned

View Answer

Explanation: If there is bijection then two sets A and B will be equinumerous and thus will have same cardinality.

5. Let a set E ={0,2,4,6,8….} of non-negative even numbers and O = {1, 3, 5, 7, 9,…..} of non-negative odd numbers then?

a) Cardinality of set E is greater than that of O

b) Cardinality of set O is greater than that of E

c) Cardinality of set E is equal to that of O

d) None of the mentioned

View Answer

Explanation: There is bijection then two sets E and O and they will be equinumerous and thus will have same cardinality.

6. Cardinality of the set of lower letter english alphabets is 26.

a) True

b) False

View Answer

Explanation: From a, b, c…z there will be 26 elements.

7. Cardinality of the set of even prime number under 10 is 4.

a) True

b) False

View Answer

Explanation: Since 2 is only even prime thus cardinality should be 1.

8. If for sets A and B there exists an injective function but not bijective function from A to B then?

a) Cardinality of A is strictly greater than B

b) Cardinality of B is strictly greater than A

c) Cardinality of B is equal to A

d) None of the mentioned

View Answer

Explanation: If there doesnot exist a bijective function from A to B that means there are some elements in B whose preimage is not in A, thus cardinality of B is strictly greater than A.

9. If cardinality of (A U B) = cardinality of A+ cardinality of B. This means ____________

a) A is a subset of B

b) B is a subset of A

c) A and B are disjoint

d) None of the mentioned

View Answer

Explanation: Thus if the cardinality of (A U B) = cardinality of A+ cardinality of B, it means they don’t have any element in common, n(A∩B) = 0.

10. If A is a subset of B and B is a subset of C, then cardinality of A U B U C is equal to ____________

a) Cardinality of C

b) Cardinality of B

c) Cardinality of A

d) None of the mentioned

View Answer

Explanation: A U B U C = C, since a, b are subsets to C.

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

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

**Related Posts:**

- Apply for Computer Science Internship
- Check Computer Science Books
- Check Discrete Mathematics Books
- Practice Computer Science MCQs
- Practice Information Technology MCQs