What is the common difference of (72,64,56,48,\ldots)?
Answer and explanation
Correct answer: -8
To find the common difference, subtract a term from the term immediately after it. Here, \(64-72=-8\) and \(56-64=-8\), so each successive term decreases by 8. Therefore, the common difference is \(-8\). The number \(8\) is only the magnitude of the decrease, not the common difference. Exam tip: use \(d=a_2-a_1\); if the terms decrease, \(d\) is negative.
Frequently asked questions
What is the correct answer to this question?
-8
Why is this the correct answer?
To find the common difference, subtract a term from the term immediately after it. Here, \(64-72=-8\) and \(56-64=-8\), so each successive term decreases by 8. Therefore, the common difference is \(-8\). The number \(8\) is only the magnitude of the decrease, not the common difference. Exam tip: use \(d=a_2-a_1\); if the terms decrease, \(d\) is negative.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Arithmetic Progressions (AP). Topic: Introduction to APs and common difference..
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