For the terms of any arithmetic progression (AP), which of the following relations is always true?
Answer and explanation
Correct answer: \(a_7+a_{19}=2a_{13}\)
Using \(a_n=a+(n-1)d\), \(a_7+a_{19}=(a+6d)+(a+18d)=2a_{13}\). So option A is always true; B has the wrong middle term. Exam tip: pair terms equidistant from the centre.
Frequently asked questions
What is the correct answer to this question?
\(a_7+a_{19}=2a_{13}\)
Why is this the correct answer?
Using \(a_n=a+(n-1)d\), \(a_7+a_{19}=(a+6d)+(a+18d)=2a_{13}\). So option A is always true; B has the wrong middle term. Exam tip: pair terms equidistant from the centre.
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.