Solution
### Related Formula
For a relation R$R$ on set A = \1, 2, 3\$A = \{1, 2, 3\}$:
- **Reflexive**: Must contain \(1,1), (2,2), (3,3)\$\{(1,1), (2,2), (3,3)\}$.
- **Transitive**: If (a,b) in R$(a,b) \in R$ and (b,c) in R$(b,c) \in R$, then (a,c) in R$(a,c) \in R$.
- **Not Symmetric**: Contains at least one element (a,b)$(a,b)$ whose inverse (b,a) notin R$(b,a) \notin R$.
### Core Logic
Since R$R$ is reflexive, it must contain exactly 3$3$ initial diagonal elements:
R_textbase = \(1,1), \, (2,2), \, (3,3)\$R_{\text{base}} = \{(1,1), \, (2,2), \, (3,3)\}$
We are given that (1,2) in R$(1,2) \in R$. So R$R$ must contain at least these 4$4$ mandatory pairs:
R supseteq \(1,1), \, (2,2), \, (3,3), \, (1,2)\$R \supseteq \{(1,1), \, (2,2), \, (3,3), \, (1,2)\}$
Total elements currently = 4. The problem sets a boundary constraint of le 6$\le 6$ total elements.
Available remaining elements to selectively append: (2,1), (2,3), (1,3), (3,1), (3,2)$(2,1), (2,3), (1,3), (3,1), (3,2)$.
### Step 1: Analyze Cases based on Element Length
- **Case 1**: Exactly 4 elements.
R = \(1,1), (2,2), (3,3), (1,2)\$R = \{(1,1), (2,2), (3,3), (1,2)\}$
This is reflexive, transitive, and not symmetric (since (2,1) notin R$(2,1) \notin R$). implies 1 text way$\implies 1 \text{ way}$.
### Step 2: Evaluate 5 and 6 Element Configurations
- **Case 2**: Exactly 5 elements.
We add one pair from the available pool. To ensure transitivity, we choose pairs like (1,3)$(1,3)$ or (3,2)$(3,2)$.
- If we add (1,3)$(1,3)$: R = dots cup \(1,3)\$R = \dots \cup \{(1,3)\}$ implies$\implies$ valid (transitive, non-symmetric).
- If we add (3,2)$(3,2)$: R = dots cup \(3,2)\$R = \dots \cup \{(3,2)\}$ implies$\implies$ valid.
Adding (2,1)$(2,1)$ or others directly breaks either transitivity or symmetric constraints. implies 2 text ways$\implies 2 \text{ ways}$.
- **Case 3**: Exactly 6 elements.
Valid configuration groups that satisfy all transitive linkages without triggering full symmetry across the board are:
1. \(2,3), (1,3)\$\{(2,3), (1,3)\}$ added
2. \(1,3), (3,2)\$\{(1,3), (3,2)\}$ added
3. \(3,1), (3,2)\$\{(3,1), (3,2)\}$ added
This yields 3 text ways$3 \text{ ways}$.
### Step 3: Calculate the Comprehensive Sum
Sum the valid configurations across all operational boundaries:
textTotal Relations = 1 + 2 + 3 = 6 quad (textour Analysis)$\text{Total Relations} = 1 + 2 + 3 = 6 \quad (\text{our Analysis})$
*(Note: Official NTA keys accepted 5 due to variant interpretation filters on transitivity bounds).*
### Pattern Recognition
When dealing with small set elements counts like n=3$n=3$, building explicit tracking trees of allowed pairs is far safer than calculating raw combinations using generalized formula subsets.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 11 Mathematics: Relations and Functions