If (a_n=20-4n), what is the value of (a_4)?
Answer and explanation
Correct answer: 4
Given \(a_n=20-4n\). To find the fourth term, substitute \(n=4\): \(a_4=20-4(4)=20-16=4\). Therefore, 4 is the correct answer. Option 8 could result from incorrectly subtracting 12 instead of calculating \(4\times4\). Exam tip: In an explicit rule, substitute the term number carefully for \(n\).
Frequently asked questions
What is the correct answer to this question?
4
Why is this the correct answer?
Given \(a_n=20-4n\). To find the fourth term, substitute \(n=4\): \(a_4=20-4(4)=20-16=4\). Therefore, 4 is the correct answer. Option 8 could result from incorrectly subtracting 12 instead of calculating \(4\times4\). Exam tip: In an explicit rule, substitute the term number carefully for \(n\).
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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