एक समान्तर श्रेणी में \(a_{11}=40\) और \(a_{19}=72\) है। \(a_4\) क्या होगा?
In an AP, \(a_{11}=40\) and \(a_{19}=72\). What is \(a_4\)?
Explanation opens after your attempt
C. (12)
Concept
\(d=\frac{72-40}{8}=4\) and \(a_4=40-7\times4=12\). When moving backward from a known term, subtract (d).
Why this answer is correct
The correct answer is C. (12). \(d=\frac{72-40}{8}=4\) and \(a_4=40-7\times4=12\). When moving backward from a known term, subtract (d).
Exam Tip
\(d=\frac{72-40}{8}=4\) और \(a_4=40-7\times4=12\)। ज्ञात पद से पीछे जाने पर (d) घटाते जाएं।
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