JEE Main 2020MathematicsSequences and SeriesEasyMCQ

JEE Main 2020 — Sequences and Series Question with Solution

JEE Main 2020 (07 Jan Shift 1)

Question

Five numbers are in A.P., whose sum is 25 and product is 2520. If one of these five numbers is -12, then the greatest number amongst them is

Choose an option

Show full solutionCorrect option: D
Correct answer
D16

Step-by-step explanation

Let term be a-2d,a-d,a,a+d,a+2d
Sum =25⇒5a=25⇒a=5
Product =2520
5-2d5-d55+d5+2d=2520
⇒25-4d225-d2=504
⇒625-100d2-25d2+4d4=504
⇒4d4-125d2+625-504=0
⇒4d4-125d2+121=0
⇒4d4-121d2-4d2+121=0
⇒d2-14d2-121=0
⇒d=±1,d=∓112
d=±1, does not give -12 as a term
∴d=112
∴ Largest term =5+2d=5+11=16

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Sequences and Series chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

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.