If the first term of an AP is (15) and the common difference is (-4), what is the (8)th term?
Answer and explanation
Correct answer: (-13)
The formula for the nth term of an AP is \(a_n=a+(n-1)d\). Here, \(a=15\), \(d=-4\), and \(n=8\). Therefore, \(a_8=15+(8-1)(-4)=15-28=-13\). Hence, \((-13)\) is correct. \((-11)\) may result from using the wrong number of steps or forgetting \((n-1)\). Exam tip: when the common difference is negative, each successive term decreases.
Frequently asked questions
What is the correct answer to this question?
(-13)
Why is this the correct answer?
The formula for the nth term of an AP is \(a_n=a+(n-1)d\). Here, \(a=15\), \(d=-4\), and \(n=8\). Therefore, \(a_8=15+(8-1)(-4)=15-28=-13\). Hence, \((-13)\) is correct. \((-11)\) may result from using the wrong number of steps or forgetting \((n-1)\). Exam tip: when the common difference is negative, each successive term decreases.
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.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
