JEE Main 2020 — Sequences And Series Question with Solution
From: JEE Main 2020 (Online) 9th January Evening Slot
Question
Let an be the nth term of a G.P. of positive terms.
and ,
then is equal to :
and ,
then is equal to :
Choose an option
Show full solutionCorrect option: A
Correct answer
A150
Step-by-step explanation
a3 + a5 + a7 + .... + a201 = 200
= 200 ....(1)
a2 + a4 + a6 + ... + a200 = 100
= 100 ....(2)
dividing (1) by (2)
we get, r = 2
adding both (1) and (2), we get
a2 + a3 + a4 + a5 + ..... + a201 = 300
r(a1 + a2 + ..... + a200) = 300
a1 + a2 + ..... + a200 =
= = 150
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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.