JEE Mains · Maths · STD 11 - 8. sequence and series
If \(a _{1}, a _{2}, a _{3} \ldots\) and \(b _{1}, b _{2}, b _{3} \ldots\) are \(A.P.\) and \(a_{1}=2, a_{10}=3, a_{1} b_{1}=1=a_{10} b_{10}\) then \(a_{4} b_{4}\) is equal to
- A \(\frac{35}{27}\)
- B \(1\)
- C \(\frac{27}{28}\)
- D \(\frac{28}{27}\)
Answer & Solution
Correct Answer
(D) \(\frac{28}{27}\)
Step-by-step Solution
Detailed explanation
\(a_{1}, a_{2}, a_{3} \ldots \text { A.P. } ; a_{1}=2 ; a_{10}=3 ; d_{1}=\frac{1}{9}\) \(b _{1}, b _{2}, b _{3}, \ldots\) \(A.P.\) \(; b _{1}=\frac{1}{2} ; b _{10}=\frac{1}{3} ; d _{2}=\frac{-1}{54}\) [Using \(a_{1} b_{1}=1=a_{10} b_{10} ; d_{1}\) and \(d_{2}\) are common…
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