Competishun Header
Competishun
Contact Us
Back

Report Issue

Jee Main 2026
02 - 04 2026 S2
Question
The mean and variance of $n$ observations are 8 and 16 , respectively. If the sum of the first ( $n-1$ ) observations is 48 and the sum of squares of the first ( $n-1$ ) observations is 496 , then the value of $n$ is : 
Select the correct option:
A
21
B
16
C
13
D
7
✓ Correct! Well done.
✗ Incorrect. Try again or view the solution.
Solution
Question Tags
JEE Main
Mathematics
Easy
Start Preparing for JEE with Competishun
YouTube
Books
App
Tests
Video Solution
BY competishun
Video Solution
Watch Solution
Filters 0
JEE Main
JEE Advance
Easy
Medium
Hard
Showing 18 questions
Q JEE MAIN 20262026
Given below are two statements
Statement I: $\mathrm{H}_2 \mathrm{O}$ molecules move from the chamber 1 to chamber 2 .
Statement II:...
JEE MainChemistryMedium
View Solution→
QJEE MAIN 20232023
Let $z$ be a complex number such that $\left|\frac{z-2 i}{z+i}\right|=2, z \neq-i$. Then $z$ lies on the circle of radius...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 2022 2022
For $z \in \mathbb{Z}$ if the minimum value of $(|z-3 \sqrt{2}|+|z-p \sqrt{2} i|)$ is $5 \sqrt{2}$, then a value of...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
Let the area enclosed by the $x$-axis, and the tangent and normal drawn to the curve $...
JEE MainMathematicsMedium
View Solution→
QJEE MAIN 20222022
Let $x=\sin \left(2 \tan ^{-1} \alpha\right)$ and $y=\sin \left(\frac{1}{2} \tan ^{-1} \frac{4}{3}\right)$. If $S=\left\{\alpha \in \mathbb{Z}: y^2=1-x\right\}$, then $...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
If the circles $x^2+y^2+6 x+8 y+16=0$ and $x^2+y^2+2^{(3-\sqrt{3})} x+2^{(4-\sqrt{6})} y=k+6 \sqrt{3}+8 \sqrt{6}, k>0$, touch internally at the point $\mathbf{P}(\alpha, \beta)$,...
JEE MainMathematicsMedium
View Solution→
QJEE MAIN 20222022
Let $a_n=\int_{-1}^n\left(1+\frac{x}{2}+\frac{x^2}{3}+\ldots . .+\frac{x^{n-1}}{n}\right) d x$ for every $n \in N$. Then the sum of all the elements of the...
JEE MainMathematicsMedium
View Solution→
QJEE MAIN 20222022
Let $f$ be a twice differentiable function on $R$. If $f^{\prime}(0)=4$ and $...
JEE MainMathematicsMedium
View Solution→
QJEE MAIN 20222022
Let $y=y(x)$ be the solution of the differential equation $\frac{d y}{d x}=\frac{4 y^3+2 y x^2}{3 x y^2+x^3}, y(1)=1$. If for...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
The sum of the maximum and minimum values of the function $f(x)=|5 x-7|+\left[x^2+2 x\right]$ in the interval $\left[\frac{5}{4}, 2\right]$, where...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20232023
Let the function $f(x)=2 x^3+(2 p-7) x^2+3(2 p-9) x-6$ have a maxima for some value of $x<0$ and a minima...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
Let $...
JEE MainMathematicsMedium
View Solution→
QJEE MAIN 20222022
Let $f(x)$ be a quadratic polynomial with leading coefficient 1 such that $f(0)=p, p \neq 0$, and $f(1)=\frac{1}{3}$. If the...
JEE MainMathematicsHard
View Solution→
QJEE MAIN 20222022
Let $A=\{1,2,3,4,5,6,7\}$. Define $B=\{T \subseteq A$ : either $1 \notin T$ or $2 \in T\}$ and $C=\{T \subseteq A: T$...
JEE MainMathematicsHard
View Solution→
QJEE MAIN 20222022
Consider the following statements : P : Ramu is intelligent. Q : Ramu is rich. R : Ramu is not...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
$2 \sin \left(\frac{\pi}{22}\right) \sin \left(\frac{3 \pi}{22}\right) \sin \left(\frac{5 \pi}{22}\right) \sin \left(\frac{7 \pi}{22}\right) \sin \left(\frac{9 \pi}{22}\right)$ is equal to :
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
If the mean deviation about median for the number 3, 5, 7, 2k, 12, 16, 21, 24 arranged in the...
JEE MainMathematicsEasy
View Solution→
QJEE MAIN 20222022
The shortest distance between the lines $\frac{x+7}{-6}=\frac{y-6}{7}=z$ and $\frac{7-x}{2}=y-2=z-6$ is
JEE MainMathematicsEasy
View Solution→