JEE Main 2020 — Sequences And Series Question with Solution
From: JEE Main 2020 (Online) 5th September Evening Slot
Question
If the sum of the first 20 terms of the series
is 460,
then x is equal to :
is 460,
then x is equal to :
Choose an option
Show full solutionCorrect option: C
Correct answer
C72
Step-by-step explanation
460 = log7 x·(2 + 3 + 4 + ..... + 20 + 21)
460 = log7 x.
460 = 230. log7 x
log7 x = 2
x = 49
460 = log7 x.
460 = 230. log7 x
log7 x = 2
x = 49
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This is a previous-year question from JEE Main 2020, 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.