JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 22 July 2021, Shift 2, Maths Q89

Question 89 of 90 in this shift, Maths question 29 of 30, Section B.

Consider the following frequency distribution : Class : 0 - 6 | 6 - 12 | 12 - 18 | 18 - 24 | 24 - 30 Frequency : a | b | 12 | 9 | 5 If mean

=\frac{309}{22}

and median

=14

, then the value

(\mathrm{a}-\mathrm{b})^2

is equal to ________.

Official answer

NTA final key.

Chapter: Statistics
Topic: Variance and SD
Idea tested: Mean of Discrete Data

Same idea in other shifts

Asked 6× in all

2 Apr 2026, Shift 1 · Q8If the mean of the data | Class | 5-10 | 10-15 | 15-20 | 20-25 | 25-30 | 30-35 | | Frequency | 2 | $k$ | 28 | 54 | $k+1$ | 5 | is $21$ ,…MediumSingle correct
11 Apr 2023, Shift 1 · Q13Let $x_1, x_2, \ldots, x_{100}$ be in an arithmetic progression, with $x_1 = 2$ and their mean equal to 200. If…MediumSingle correct
31 Aug 2021, Shift 1 · Q90The mean of 10 numbers $7\times8,\ 10\times10,\ 13\times12,\ 16\times14,\ ...$ is __________.MediumNumerical value
18 Mar 2021, Shift 1 · Q87The mean age of 25 teachers in a school is 40 years. A teacher retires at the age of 60 years and a new teacher is appointed in his place.…EasyNumerical value
6 Sep 2020, Shift 2 · Q75Consider the data on $x$ taking the values $0, 2, 4, 8, \ldots, 2^n$ with frequencies ${}^nC_0, {}^nC_1, {}^nC_2, \ldots, {}^nC_n$ …MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.