Home
Class 12
MATHS
Consider the set A = {1,3,5}. Assertio...

Consider the set A = {1,3,5}.
Assertion (A): The number of reflexive relations on set A is `2^(9)` .
Reason (R): A relation is said to be reflexive if `A in A`.

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 and R is True

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine whether the assertion and reason provided are true or false regarding the number of reflexive relations on the set \( A = \{1, 3, 5\} \). ### Step-by-Step Solution: 1. **Understanding Reflexive Relations**: A relation on a set is called reflexive if every element is related to itself. For a set \( A \) with \( n \) elements, a reflexive relation must include all pairs of the form \( (a, a) \) for each \( a \in A \). 2. **Identifying the Set**: The set \( A \) has 3 elements: \( 1, 3, 5 \). Therefore, the reflexive pairs that must be included in any reflexive relation on this set are: - \( (1, 1) \) - \( (3, 3) \) - \( (5, 5) \) 3. **Counting Total Pairs**: The total number of possible pairs (relations) that can be formed from the set \( A \) is \( n^2 \), where \( n \) is the number of elements in the set. For \( A \): \[ n = 3 \implies n^2 = 3^2 = 9 \] Thus, there are 9 possible pairs. 4. **Determining Reflexive Relations**: Since a reflexive relation must include the 3 reflexive pairs mentioned above, we are left with \( 9 - 3 = 6 \) pairs that can either be included or excluded from the relation. These pairs are: - \( (1, 3) \) - \( (1, 5) \) - \( (3, 1) \) - \( (3, 5) \) - \( (5, 1) \) - \( (5, 3) \) 5. **Calculating the Number of Reflexive Relations**: Each of the 6 remaining pairs can either be included in the relation or not, giving us \( 2 \) choices (include or exclude) for each pair. Therefore, the total number of reflexive relations is: \[ 2^6 = 64 \] 6. **Conclusion**: The assertion states that the number of reflexive relations is \( 2^9 \). We found that it is \( 2^6 \), so the assertion is **false**. The reason states that a relation is reflexive if \( A \in A \), which is a misinterpretation of reflexivity. The reason is also **false**. ### Final Answer: - Assertion (A): False - Reason (R): False
Promotional Banner

Similar Questions

Explore conceptually related problems

If A={1,2,3}, the number of reflexive relations in A is

Let set A=(a,b,c), then number of possible reflexive relations on set A are

The number of reflexive relations of a set with four elements is equal to

Let R be a reflexive relation on a set A and I be the identity relation on A.Then

Consider the set A={1,2,3,4} . Which of the following relations R form a reflexive relation?

Write the smallest reflexive relation on set A = {1, 2, 3, 4, 5}.