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Saturday, 31 October

JEE Main · Maths · Statistics

Effect of Linear Transformations

JEE Main asked Effect of Linear Transformations 4 times in 4 of the 108 shifts Lumi analysed, in 2020 and 2021. It belongs to Variance and SD, in Statistics (Maths). The longest wait between two years asking it was 1 year. In 2020 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
4
in 4 shifts
Years
2 of 8
First asked
2020
last in 2021
Pattern
Gone quiet
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2020 and 2021. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Maths questions.

00.150.30’170.25’200.03’210’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 3 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20220 of 24
  • 20211 of 24
  • 20203 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: calculation.

  • Find unknown data from mean and variance
  • Effect of linear transformation on mean and sd

Difficulty

Easy 0Medium 4Hard 0

Every question was multiple choice.

Every question

All 4 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 18 Mar 2021, Shift 2 · Q64Let in a series of 2n2n observations, half of them are equal to a and remaining half are equal to −-a. Also by adding a constant b in…MediumSingle correct
  2. 2 Sep 2020, Shift 1 · Q67Let X={x∈N:1≤x≤17}X=\{x\in\mathbf{N} : 1\le x\le 17\} and Y={ax+b:x∈XY=\{ax+b : x\in X and a,b∈R,a>0}a, b\in\mathbf{R}, a>0\}. If mean and variance of elements of Y…MediumSingle correct
  3. 9 Jan 2020, Shift 1 · Q68Let the observations xi(1≤i≤10)x_i(1\le i\le 10) satisfy the equations, ∑i=110(xi−5)=10\sum_{i=1}^{10}(x_i-5)=10 and ∑i=110(xi−5)2=40\sum_{i=1}^{10}(x_i-5)^2=40. If μ\mu…MediumSingle correct
  4. 8 Jan 2020, Shift 1 · Q67The mean and the standard deviation (s.d.) of 10 observations are 20 and 2 respectively. Each of these 10 observations is multiplied by p…MediumSingle correct

Shifts: 8 Jan 2020, Shift 1, 9 Jan 2020, Shift 1, 2 Sep 2020, Shift 1, 18 Mar 2021, Shift 2.

Same topic

Other ideas in Variance and SD

Variance and SD has 20 ideas JEE Main has asked; 10 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas