समांतर श्रेणी में \(a_7=34\) और \(a_{12}=69\) है। \(a_1\) क्या है?
In an arithmetic progression, \(a_7=34\) and \(a_{12}=69\). What is \(a_1\)?
Explanation opens after your attempt
A. (-8)
Concept
\(a_{12}-a_7=5d=35\), so (d=7) and (a_1=34-6(7)=-8). First find (d), then move backward.
Why this answer is correct
The correct answer is A. (-8). \(a_{12}-a_7=5d=35\), so (d=7) and (a_1=34-6(7)=-8). First find (d), then move backward.
Exam Tip
\(a_{12}-a_7=5d=35\), इसलिए (d=7) और (a_1=34-6(7)=-8)। पहले (d) निकालकर पीछे जाएं।
Login to save your score, XP, coins and progress.
