JEE Main 2020 · MathsNumerical answerNumerical valueMediumCalculation

JEE Main 6 September 2020, Shift 2, Maths Q75

Question 75 of 75 in this shift, Maths question 25 of 25.

Consider 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

respectively. If the mean of this data is

\frac{728}{2^n}

, then n is equal to ________.

Official answer

6.00

NTA final key (Sep 2020).

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

Same idea in other shifts

Asked 4× 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
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

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 42 of the 174 JEE Main shifts held from 2017 to 2026.