Page 18 - Mathematics Class - XI

Case-Study Based Questions
Case-Study Based Questions

A class teacher of class - 11 prepares three sets A, B and C based upon the set theory for assessment of
her class. Here A = {1, 3, 5, 7, 9}, B = {2, 6, 8} and C = {2, 3, 5, 7}.
Now answers the following questions which are based on above sets.

1. Find A ∩ B
(a) {2, 3, 5, 7} (b) φ (c) {1, 3, 5, 7, 9, 8} (d) {1, 2, 3, 5, 6, 7, 8, 9}

2. Find A ∩ C
(a) {3, 5, 7} (b) {1, 2, 3, 5, 7, 9} (c) φ (d) {1, 3}
3. Find B ∩ C
(a) φ (b) {2} (c) {2, 3, 5, 6, 7, 8} (d) None of these

4. Which of the following is correct for sets A and B to be disjoint.
(a) A ∩ B = φ (b) A ∩ B ≠ φ (c) A ∪ B = φ (d) A ∪ B ≠ φ

5. Calculate the value of n{P(A)}
(a) 16 (b) 32 (c) 24 (d) 25

Assertion-Reason Based Questions
Assertion-Reason Based Questions
Directions for Questions 1 to 3: In each of the questions given below, there are two statements marked as
Assertion (A) and Reason (R). Mark your answer as per the codes provided below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false. (d) A is false but R is true.

Q. 1. Assertion (A) : A = {a, b} and B = {a, b, c} then A is subset of B.
Reason (R) : All subsets are finite sets.
Q. 2. Assertion (A) : The collection of all-natural numbers less than 100 is a set.
Reason (R) : A set is a well-defined collection of distinct objects.
Q. 3. Assertion (A) : A set of positive integers greater than 100 is infinite.
Reason (R) : A set of prime number less than 99 is finite.

Answers

Case-Study Based Questions: 1. (b) 2. (a) 3. (b) 4. (a) 5. (d)
Assertion-Reason Based Questions: 1. (c) 2. (a) 3. (b)

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