Which of the following nth-term expressions represents an AP in which each successive term decreases by 3?
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Answer and explanation
Correct answer: \(a_n=20-3n\)
An AP has nth term \(a_n=a+(n-1)d\). In \(20-3n\), the coefficient of n is \(-3\), so consecutive terms differ by \(-3\). For \(20-3n^2\), the difference is not constant. Exam tip: check the coefficient of n in a linear expression.
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What is the correct answer to this question?
\(a_n=20-3n\)
Why is this the correct answer?
An AP has nth term \(a_n=a+(n-1)d\). In \(20-3n\), the coefficient of n is \(-3\), so consecutive terms differ by \(-3\). For \(20-3n^2\), the difference is not constant. Exam tip: check the coefficient of n in a linear expression.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Arithmetic Progressions (AP). Topic: Finding the $n$th term of an AP.
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