In the arithmetic progression (24,30,36,\ldots), if (a_n=102), what is (n)?
Answer and explanation
Correct answer: 14
Here, the first term is 24 and the common difference is 6. Thus, \(a_n=24+(n-1)\times6\). From \(24+6(n-1)=102\), we get \(6(n-1)=78\), so \(n-1=13\) and hence \(n=14\). Option 13 is the value of \(n-1\), not the term number. Exam tip: after finding \(n-1\), remember to add 1 to obtain \(n\).
Frequently asked questions
What is the correct answer to this question?
14
Why is this the correct answer?
Here, the first term is 24 and the common difference is 6. Thus, \(a_n=24+(n-1)\times6\). From \(24+6(n-1)=102\), we get \(6(n-1)=78\), so \(n-1=13\) and hence \(n=14\). Option 13 is the value of \(n-1\), not the term number. Exam tip: after finding \(n-1\), remember to add 1 to obtain \(n\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Arithmetic Progression.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
