The GATE Grind

GATE Standard Univariate Distributions: Continuous Distributions – Previous Year Questions

12 GATE previous year questions on Continuous Distributions (Standard Univariate Distributions, Statistics) with answers and explanations, from every paper.

  1. GATE 2022 ST Q25 (1 mark, Numerical answer) – X,Y are independent exponential variables with E X²=1/2 and E Y²=2/9. Find P(X<2Y) to two decimals.
  2. GATE 2023 ST Q16 (1 mark, Multiple choice) – X has density αλ x(α−1) exp(−λxα) for x>0,zero otherwise,α,λ>0. Its median is 1 and third quartile is 2. Find (α,λ).
  3. GATE 2023 ST Q18 (1 mark, Multiple choice) – X has gamma density λα x(α−1)e(−λx)/Γ(α),x>0,α,λ>0. Which claim is NOT true?
  4. GATE 2023 ST Q37 (2 marks, Multiple choice) – X has density 1/x² for x≥1,zero otherwise. For Y=ln X,find P(Y<1 Y<2).
  5. GATE 2024 ST Q19 (1 mark, Multiple choice) – X has beta density Γ(α+β)x(α−1)(1−x)(β−1)/[Γ(α)Γ(β)] on (0,1),α,β>0. If E X=1/3,E X²=1/6, find α+3β.
  6. GATE 2024 ST Q40 (2 marks, Multiple choice) – Checkout service times are independent exponential with density e(−x/10)/10,x≥0. On arrival one customer is already being served and has spent five…
  7. GATE 2024 ST Q42 (2 marks, Multiple choice) – The X i are iid N(μ,σ²). I:if [√5/(σ(2n+1))]Σᵢ₌₁ⁿi(X i−μ) is N(0,1), then n=2. II:E[−ln Φ((X₁−μ)/σ)]³=6. Which hold?
  8. GATE 2025 ST Q40 (2 marks, Multiple choice) – X>0 has lognormal density f(x)=( x2)-1[-12(( x-)/)2]. If ln(E(X²)/(E X)²)=4, find Var(ln X).
  9. GATE 2025 ST Q59 (2 marks, Numerical answer) – Service densities at pumps P₁,P₂ are λe(−λx) and λ²xe(−λx),x>0. Each pump is selected with probability 1/2. If the chance of service exceeding one…
  10. GATE 2026 ST Q16 (1 mark, Multiple choice) – Independent identically distributed normal X,Y satisfy P(X+2Y≤3)=P(2X−Y≥4). Find E(X).
  11. GATE 2026 ST Q29 (1 mark, Numerical answer) – Independent X₁,X₂,X₃ have densities ke(−kx),x>0, for k=1,2,3 respectively. For Y=min(X₁,X₂,X₃), find E(3Y²−Y) (integer).
  12. GATE 2026 ST Q62 (2 marks, Numerical answer) – For X~N(3,1), find E[X⁴(X−3)] (integer).