If (a_n=200-12n), what is the value of (a_9)?
Answer and explanation
Correct answer: 92
The given rule is \(a_n=200-12n\). Substituting \(n=9\), we get \(a_9=200-12\times9=200-108=92\). Therefore, 92 is correct. A value such as 88 results from an arithmetic error after substitution. Exam tip: substitute the term number first, then perform multiplication before subtraction.
Frequently asked questions
What is the correct answer to this question?
92
Why is this the correct answer?
The given rule is \(a_n=200-12n\). Substituting \(n=9\), we get \(a_9=200-12\times9=200-108=92\). Therefore, 92 is correct. A value such as 88 results from an arithmetic error after substitution. Exam tip: substitute the term number first, then perform multiplication before subtraction.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Explicit or general rule.
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