JEE Main 2019MathematicsSequences and SeriesMediumMCQ

JEE Main 2019 — Sequences and Series Question with Solution

JEE Main 2019 (12 Jan Shift 2)

Question

If the sum of the first 15 terms of the series 343+1123+2143+33+334 3+… is equal to 225K, then K is equal to :

Choose an option

Show full solutionCorrect option: B
Correct answer
B27

Step-by-step explanation

Given series, 343+643+943+1243+1543+…15 terms

=34313+23+33+…+153 

=276415×1622   ∵∑n=1n=nn3=nn+122 

=2764×225×641=27×225 

Since, given 225K=27×225 

⇒K=27

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About this question

This is a previous-year question from JEE Main 2019, 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.