The first three terms of an arithmetic progression are 3, 8, 13. Which of the following expressions represents the nth term of this AP?
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Answer and explanation
Correct answer: \(5n-2\)
Here, the first term is \(a=3\) and the common difference is \(d=8-3=5\). Thus, \(a_n=a+(n-1)d=3+5(n-1)=5n-2\). Option B gives 7 when \(n=1\), not 3. Exam tip: identify \(a\) and \(d\) first.
Frequently asked questions
What is the correct answer to this question?
\(5n-2\)
Why is this the correct answer?
Here, the first term is \(a=3\) and the common difference is \(d=8-3=5\). Thus, \(a_n=a+(n-1)d=3+5(n-1)=5n-2\). Option B gives 7 when \(n=1\), not 3. Exam tip: identify \(a\) and \(d\) first.
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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