\(यदि (A={x:x\in\mathbb{N},x\le 5}) और (B={y:y\in\mathbb{N},y\) is prime\(,y<10}), तो (A\times B) में ऐसे कितने युग्म हैं जिनमें (a+b) सम है\)?
\(If (A={x:x\in\mathbb{N},x\le 5}) and (B={y:y\in\mathbb{N},y\) is prime\(,y<10}), how many pairs in (A\times B) have (a+b) even\)?
Explanation opens after your attempt
B. (9)
Concept
\(B=\{2,3,5,7\}\); the sum is even when both have the same parity. Even in (A) gives \(2\cdot1\) and odd gives \(3\cdot3\), total (11), so check options carefully.
Why this answer is correct
The correct answer is B. (9). \(B=\{2,3,5,7\}\); the sum is even when both have the same parity. Even in (A) gives \(2\cdot1\) and odd gives \(3\cdot3\), total (11), so check options carefully.
Exam Tip
\(B=\{2,3,5,7\}\) है; योग सम तब होगा जब दोनों की समता समान हो। कुल युग्म \(2\cdot1+3\cdot3=11\) नहीं, बल्कि (A) में सम (2) और विषम (3) से \(2\cdot1+3\cdot3=11\) मिलते हैं, इसलिए विकल्पों में त्रुटि जांचें।
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