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71 questions match · page 1 of 3

CSIR NET June 2025 · Part A (2 Marks)#exactly-two-excludes-the-centre-region-where-all-three-overlap

A Venn diagram shows the numbers of players playing one or more than one sport among Football, Cricket and Tennis: 18 play Football only, 24 play Cricket only, 20 play Tennis only, 7 play Football and Cricket but not Tennis, 11 play Football and Tennis but not Cricket, 8 play Cricket and Tennis but not Football, and 4 play all three sports. The percentage of players who play exactly two sports is closest to ____%.

Single choice

CSIR NET December 2025 · Part A (2 Marks)#buying-some-apples-rules-out-the-zero-apples-case

A lady bought some apples, each costing Rs. 25, and some bananas each costing Rs. 6, for a total of Rs. 378. In how many ways could she have chosen the numbers of apples and bananas?

Single choice

CSIR NET June 2025 · Part B (3 Marks)Analysis & Linear Algebra#the-k-at-least-1-is-what-makes-these-strict-inequalities

Let p, q be non-negative integers. Consider the following statements: (A) There is an integer k ≥ 1 such that p + k = q. (B) There is an integer k ≥ 1 such that q + k = p. Which of the following statements is true?

Single choice · The Real Line

CSIR NET June 2025 · Part B (3 Marks)Analysis & Linear Algebra#rank-exactly-one-excludes-the-zero-matrix-and-is-not-the-invertible-co

Let 𝔽5_{5} denote the field with 5 elements. How many 2 × 2 matrices with entries in 𝔽5_{5} have rank one?

Single choice · Vector Spaces and Linear Maps

CSIR NET June 2025 · Part B (3 Marks)Complex Analysis, Algebra & Topology#the-2-pi-r-arc-length-factor-forces-f-to-vanish-so-c-is-exactly-0

Let f:C→Cf : \mathbb{C} \to \mathbb{C} be a polynomial map. For R > 0, let γR:[0,1]→C\gamma_R : [0, 1] \to \mathbb{C} be the map t ↦ Re2πitRe^{2\pi{}it}. Suppose that there exists c∈Rc \in \mathbb{R} such that ∫01\int_{0}^{1} |(f ∘ γR)(t)γR′(t)\gamma_R)(t) \gamma'_R(t)| dt → c as R→∞R \to \infty. Which of the following statements is FALSE?

Single choice · Cauchy Theory

CSIR NET June 2025 · Part B (3 Marks)Complex Analysis, Algebra & Topology#the-line-misses-the-origin-so-the-forced-constant-is-non-zero

Let f be an entire function such that f(C)⊂f(\mathbb{C}) \subset {x + iy | y = x + 1}. Which of the following statements is true?

Single choice · Cauchy Theory

CSIR NET June 2025 · Part B (3 Marks)ODE, PDE & Applied Mathematics#the-point-asked-about-lies-on-the-initial-curve-so-the-data-answers-it

Let u = u(x, y) be the solution to the Cauchy problem (y+u)∂u/∂x+y∂u/∂y=x−y,x∈R,y>0,u(x,1)=1+x,x∈R(y + u)\partial{}u/\partial{}x + y \partial{}u/\partial{}y = x - y, x \in \mathbb{R}, y > 0, u(x, 1) = 1 + x, x \in \mathbb{R}. Then which of the following statements is true?

Single choice · Partial Differential Equations

CSIR NET June 2025 · Part B (3 Marks)Probability, Statistics & Linear Programming#r-being-positive-does-not-mean-both-values-actually-occur

Suppose that we have a data set consisting of 2n + 1 observations for some n∈Nn \in \mathbb{N}. Value of each observation is either x or x + r, where x∈N,r≥0x \in \mathbb{N}, r \ge 0. Then, which of the following statements is always true?

Single choice · Probability

CSIR NET June 2025 · Part B (3 Marks)Probability, Statistics & Linear Programming#1-is-not-prime-so-the-odd-faces-do-not-all-carry-the-doubled-weight

A biased six-faced die is tossed once. Suppose that the probability of any prime number showing up is twice that of any non-prime number showing up. Then, the probability that an odd number will show up is

Single choice · Probability

CSIR NET December 2025 · Part B (3 Marks)Analysis & Linear Algebra#alpha-less-than-one-diverges-regardless-of-beta-only-alpha-equals-one

Let α,β∈(0,∞)\alpha, \beta \in (0, \infty). Consider the infinite series ∑n≥4\sum_{n\ge4} 1/[n(logen)α(loge(logen))β]1/[n(log_{e} n)^\alpha (log_{e}(log_{e} n))^\beta]. Which of the following statements is true?

Single choice · The Real Line

CSIR NET December 2025 · Part B (3 Marks)Probability, Statistics & Linear Programming#a-target-value-can-be-in-the-range-and-still-have-probability-zero-in

Let {Yn:n≥1Y_{n} : n \ge 1} be a sequence of independent and identically distributed random variables, where Y1Y_{1} ~ Bernoulli(1/2). Define Z=∑n=1∞Z = \sum_{n=1}^\infty 4Yn/5n4Y_{n}/5^{n}. Then, which of the following statements is true?

Single choice · Probability

CSIR NET June 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#q-of-v-vanishing-makes-the-quadratic-in-alpha-linear-so-there-is-one-r

Let B(v, w) be a nondegenerate symmetric bilinear form on R2\mathbb{R}^{2} and let q(v) = B(v, v) be the corresponding quadratic form. Suppose there exist vectors v,w∈R2v, w \in \mathbb{R}^{2} such that B(v, v) = 0 and B(v, w) ≠ 0. Which of the following statements are necessarily true?

Multi-select · full marks only for the exact set · Inner Product Spaces and Forms

CSIR NET June 2025 · Part C (4.75 Marks)ODE, PDE & Applied Mathematics#the-integral-runs-past-the-data-so-the-free-endpoint-over-determines-t

For a,b,c∈Ra, b, c \in \mathbb{R}, consider the variational problem: Minimize J[y]=∫02[a(y′)2+2J[y] = \int_{0}^{2} [a(y')^{2} + 2byy′ + cy2]^{2}] dx, subject to y(0) = 10, y(1) = 100. Then which of the following statements are true?

Multi-select · full marks only for the exact set · Calculus of Variations

CSIR NET June 2025 · Part C (4.75 Marks)Probability, Statistics & Linear Programming#the-cdf-jumps-at-0-and-at-2-so-there-are-atoms-either-side-of-the-dens

Let X be a random variable with the cumulative distribution function F_X(x) = 0 if x < 0, F_X(x) = (x + 2)/5 if 0 ≤ x < 2, and F_X(x) = 1 if x ≥ 2. Then, which of the following statements are true?

Multi-select · full marks only for the exact set · Probability

CSIR NET June 2025 · Part C (4.75 Marks)Probability, Statistics & Linear Programming#theta-is-at-most-the-minimum-so-the-interval-cannot-reach-above-y

Let X1,X2,…,XnX_{1}, X_{2}, \dots, X_{n} be independent and identically distributed random variables with the probability density function f(x|θ)=\theta) = e−(x−θ)e^{-(x-\theta)} if x≥θx \ge \theta, and 0 otherwise, where θ∈R\theta \in \mathbb{R} is the unknown parameter. Further, let Y=min⁡(X1,X2,…,Xn)Y = \min(X_{1}, X_{2}, \dots, X_{n}). Which of the following are confidence intervals for θ\theta with the confidence coefficient (1−α)(1 - \alpha), where α∈(0,1)\alpha \in (0, 1)?

Multi-select · full marks only for the exact set · Probability

CSIR NET June 2025 · Part C (4.75 Marks)Probability, Statistics & Linear Programming#the-sum-from-3-to-10-has-eight-terms-so-the-t-has-8-degrees-of-freedom

Let (X1,Y1),(X2,Y2),…,(X10,Y10)(X_{1}, Y_{1}), (X_{2}, Y_{2}), \dots, (X_{10}, Y_{10}) be a random sample from a bivariate normal distribution BVN(μ1,μ2,σ12,σ22,ρ)(\mu_{1}, \mu_{2}, \sigma_{1}^{2}, \sigma_{2}^{2}, \rho) with μ1=5,μ2=6,σ12=4,σ22=9\mu_{1} = 5, \mu_{2} = 6, \sigma_{1}^{2} = 4, \sigma_{2}^{2} = 9 and ρ=1/2\rho = 1/2. Then, which of the following statements are true?

Multi-select · full marks only for the exact set · Linear Models and Multivariate

CSIR NET June 2025 · Part C (4.75 Marks)Probability, Statistics & Linear Programming#for-negative-rho-the-leading-eigenvalue-is-1-minus-rho-not-1-plus-2-rh

Let the random vector (X1,X2,X3)T(X_{1}, X_{2}, X_{3})^{T} have the positive definite dispersion matrix with rows (1,ρ,ρ),(ρ,1,ρ)(1, \rho, \rho), (\rho, 1, \rho) and (ρ,ρ,1)(\rho, \rho, 1). Then, which of the following statements are true?

Multi-select · full marks only for the exact set · Linear Models and Multivariate

CSIR NET June 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#the-a0-equals-0-block-carries-no-weight-so-it-can-hide-infinite-mass

Let μ\mu denote the Lebesgue measure on R\mathbb{R}. Suppose that f is a non-negative Lebesgue measurable function on R\mathbb{R}. Let 0=a0<a1<a2<⋯0 = a_{0} < a_{1} < a_{2} < \cdots be an unbounded sequence such that an+1a_{n+1} ≤ can_{n} for some real number c and for all n ≥ 1. Let A_k = {x∈Rx \in \mathbb{R} | a_k ≤ f(x) < ak+1a_{k+1}} for each k ≥ 0. Which of the following statements are true?

Multi-select · full marks only for the exact set · Lebesgue Measure and Integration

CSIR NET June 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#t-has-norm-exactly-1-so-it-is-not-a-contraction-but-its-square-is

Let C[0, 1] be the R−\mathbb{R}-vector space of real valued continuous functions equipped with the norm ‖f‖ = supx∈[0,1]sup_{x\in[0,1]} |f(x)|. Let T : C[0, 1] → C[0, 1] be defined as T(f)(x)=∫0T(f)(x) = \int_{0}ˣ f(t)dt, for x ∈ [0, 1]. Let Tn=TT^{n} = T ∘ T ∘ ⋯ ∘ T (n times). Which of the following statements are true?

Multi-select · full marks only for the exact set · Metric Spaces

CSIR NET December 2025 · Part C (4.75 Marks)Probability, Statistics & Linear Programming#both-support-constraints-are-lower-bounds-on-theta-so-the-mle-is-their

Let X1,X2,…,Xn(n≥2)X_{1}, X_{2}, \dots, X_{n} (n\ge2) be a random sample from Uniform[−3θ/2,θ/2][-3\theta/2, \theta/2] distribution, where θ>0\theta>0 is an unknown parameter. Let Xˉ,X(1){\bar{X}}, X_{(1)} and X(n)X_{(n)} denote respectively the mean, the smallest order statistic and the largest order statistic of the sample. Then which of the following statements are true?

Multi-select · full marks only for the exact set · Estimation

CSIR NET December 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#rank-0-means-only-the-zero-matrix-so-that-orthogonality-condition-is-v

For n≥3, consider the space Mn(C)M_{n}(\mathbb{C}) of n×n complex matrices endowed with the inner product ⟨A,B⟩ = Trace(A*B). For 0≤k≤n, let Wk=W_{k} = {A∈Mn(C)A \in M_{n}(\mathbb{C}) : ⟨A,B⟩=0 for all B∈Mn(C)B \in M_{n}(\mathbb{C}) with rank k}. Which of the following statements are necessarily true?

Multi-select · full marks only for the exact set · Inner Product Spaces and Forms

CSIR NET December 2025 · Part C (4.75 Marks)#31-days-beats-30-possible-borrower-lender-pairs-by-exactly-one-thats-t

There are six persons. On each day of the year 2024 at least one of them borrowed money from another. A person P is labeled troublesome in a calendar month M of 2024 if P borrowed from the same person at least twice during month M. Which of the following statements are necessarily true?

Multi-select · full marks only for the exact set

CSIR NET December 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#a-strictly-positive-integrand-over-a-positive-length-interval-can-appr

Let f:(0,∞)→(0,∞)f : (0,\infty) \to (0,\infty) be the function defined by f(x)=∫0f(x) = \int_{0}ˣ t/(1+t2)\sqrt{t}/(1+t^{2}) dt, where t\sqrt{t} denotes the positive square root for t>0. Which of the following statements are true?

Multi-select · full marks only for the exact set · Integration

CSIR NET December 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#f2-is-continuous-everywhere-so-it-cannot-mask-f1-s-jump-at-x-equals-1

Consider the following real-valued functions F1F_{1} and F2F_{2} defined on R\mathbb{R}, given by F1(x)=1F_{1}(x)=1 if x≥1, 0 otherwise, and F2(x)=∫0F_{2}(x)=\int_{0}ˣexp(−t)dt if x≥0, 0 otherwise. Define another function F:R→[0,1]F:\mathbb{R}\to[0,1] by F(x)=(2/3)F1(x)+(1/3)F2(x)F(x)=(2/3)F_{1}(x)+(1/3)F_{2}(x) for all x∈Rx\in\mathbb{R}. Which of the following statements are true?

Multi-select · full marks only for the exact set · Continuity and Differentiation

CSIR NET December 2025 · Part C (4.75 Marks)Analysis & Linear Algebra#non-negative-quietly-admits-zero-which-breaks-the-strict-positivity-th

Let V be a finite-dimensional R−\mathbb{R}-vector space and T:V→V a linear operator such that T2T^{2} is diagonalizable over R\mathbb{R}. Which of the following statements are necessarily true?

Multi-select · full marks only for the exact set · Eigenvalues and Canonical Forms

Session · 0 answered · — accuracy