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Let R be a reflexive relation on a finit...

Let R be a reflexive relation on a finite set A having n elements and let there be m ordered pairs in R, then

A

`m ge n`

B

`m le n`

C

`m = n`

D

none of these

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The correct Answer is:
To solve the problem, we need to analyze the properties of reflexive relations on a finite set. Let's break it down step by step. ### Step-by-Step Solution: 1. **Understanding Reflexive Relations**: A relation \( R \) on a set \( A \) is called reflexive if every element in \( A \) is related to itself. This means that for every element \( a \in A \), the ordered pair \( (a, a) \) must be in \( R \). 2. **Counting Ordered Pairs**: Given that the set \( A \) has \( n \) elements, we can conclude that there are \( n \) ordered pairs of the form \( (a_i, a_i) \) for each element \( a_i \) in \( A \). Therefore, there are at least \( n \) ordered pairs in the relation \( R \). 3. **Total Ordered Pairs in Relation**: The total number of ordered pairs in a relation on a set with \( n \) elements can vary. While we must have at least \( n \) pairs due to the reflexive property, \( R \) can also include additional pairs. For example, if \( R \) includes pairs like \( (a_i, a_j) \) where \( i \neq j \), the total number of pairs \( m \) can exceed \( n \). 4. **Conclusion**: Since \( R \) must include at least the \( n \) pairs \( (a_1, a_1), (a_2, a_2), \ldots, (a_n, a_n) \), we can conclude that: \[ m \geq n \] This means that the number of ordered pairs \( m \) in the reflexive relation \( R \) is at least equal to the number of elements \( n \) in the set \( A \). ### Final Result: Thus, the statement that \( m \) (the number of ordered pairs in \( R \)) is greater than or equal to \( n \) (the number of elements in \( A \)) is true.
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OBJECTIVE RD SHARMA ENGLISH-CARTESIAN PRODUCT OF SETS AND RELATIONS -Exercise
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  11. Which one of the following relations on R is an equivalence relation?

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  12. Let X be a family of sets and R be a relation on X defined by A is dis...

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  14. Let R and S be two non-void relations on a set A. Which of the followi...

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  15. If R be a relation lt from A = {1, 2, 3, 4} to B = {1, 3, 5}, i.e. (a,...

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