Which option correctly gives the first term and common difference of the AP whose nth term is \(a_n=5-2n\)?
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Answer and explanation
Correct answer: First term \(3\), common difference \(-2\)
Rewrite \(5-2n\) as \(3+(n-1)(-2)\), which matches \(a+(n-1)d\). Thus \(a=3\) and \(d=-2\). Option B wrongly treats the constant 5 as the first term. Exam tip: compare with the standard form first.
Frequently asked questions
What is the correct answer to this question?
First term \(3\), common difference \(-2\)
Why is this the correct answer?
Rewrite \(5-2n\) as \(3+(n-1)(-2)\), which matches \(a+(n-1)d\). Thus \(a=3\) and \(d=-2\). Option B wrongly treats the constant 5 as the first term. Exam tip: compare with the standard form 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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