JEE Main 2022MathematicsSequences and SeriesEasyMCQ

JEE Main 2022 — Sequences and Series Question with Solution

JEE Main 2022 (27 Jun Shift 2)

Question

If a1,a2,a3… and b1,b2,b3…. are A.P. and a1=2,a10=3,a1b1=1=a10b10 then a4b4 is equal to

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Show full solutionCorrect option: A
Correct answer
A2827

Step-by-step explanation

Given, a1,a2,a3......& b1,b2,b3.....are in A.P

Also given, a1=2, a10=3

and a1b1=1=a10b10

So b1=1a1=12 and b10=1a10=13

Now using nth term formula we get, a10=a1+9da⇒3=2+9da

⇒da=19

Using same formula we get,

 b10=b1+9db  ⇒13=12+9db  ⇒db=-154

Now calculating a4b4=a1+3dab1+3db

=2+3×1912+3×-154

= 73×818=5654=2827

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About this question

This is a previous-year question from JEE Main 2022, covering the Sequences and Series chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.