JEE Main 2021MathematicsStatisticsEasyNumerical

JEE Main 2021 — Statistics Question with Solution

JEE Main 2021 (24 Feb Shift 2)

Question

If the variance of 10 natural numbers 1, 1, 1, …, 1, k is less than 10, then the maximum possible value of k is ___________.

Enter your answer

Show full solutionCorrect answer: 11
Correct answer
11

Step-by-step explanation

σ2=Σx2n-Σxn2

=9+k210-9+k102<10

90+10k2-81-k2-18k<1000

9k2-18k-991<0

k2-2k<9919

k-12<10009

-10103<k-1<10103

k<10103+1

k≤11

Maximum value of k is 11.

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Statistics 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 2021, covering the Statistics 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.