What is the common difference in the sequence (2a,2a-5,2a-10,\ldots)?
Answer and explanation
Correct answer: \(-5\)
The common difference is found by subtracting a term from the next term: \((2a-5)-2a=-5\). Also, \((2a-10)-(2a-5)=-5\), confirming that the difference is constant. Each next term decreases by 5, so the common difference is \(-5\); \(5\) is only the magnitude of the decrease. Exam tip: always keep the sign while writing the common difference.
Frequently asked questions
What is the correct answer to this question?
\(-5\)
Why is this the correct answer?
The common difference is found by subtracting a term from the next term: \((2a-5)-2a=-5\). Also, \((2a-10)-(2a-5)=-5\), confirming that the difference is constant. Each next term decreases by 5, so the common difference is \(-5\); \(5\) is only the magnitude of the decrease. Exam tip: always keep the sign while writing the common difference.
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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