Relation “Less Than” from A to B

📺 Video Explanation

📝 Question

Let:

\[ A = \{3,5,7\}, \quad B = \{2,4,9\} \]

Relation \( R \) is defined as:

\[ R = \{(x,y) : x \in A,\ y \in B,\ x < y\} \]

Write \( R \) as a set of ordered pairs.

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✅ Solution

🔹 Step 1: Compare Elements

• For \( x = 3 \): (3,4), (3,9) ✔
• For \( x = 5 \): (5,9) ✔
• For \( x = 7 \): (7,9) ✔

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🔹 Step 2: Write Relation

\[ R = \{(3,4), (3,9), (5,9), (7,9)\} \]

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🎯 Final Answer

\[ \boxed{R = \{(3,4), (3,9), (5,9), (7,9)\}} \]

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🚀 Exam Insight

• Compare each element of A with all elements of B
• Include only pairs where condition is satisfied
• Systematic checking avoids missing pairs