The GATE Grind

GATE Mathematics Foundation: Probability and Statistics – Previous Year Questions

12 GATE previous year questions on Probability and Statistics (Mathematics Foundation, Environmental Science and Engineering) with answers and explanations, from every paper.

  1. GATE 2021 ES Q37 (2 marks, Multiple choice) – A biased die has faces k=1,…,6 with P(k) proportional to k². Find probability of an even result.
  2. GATE 2022 ES Q11 (1 mark, Multiple choice) – Arsenic concentrations (mg/L) are .10,.12,.20,.05,.40,.30,.35. Which describes their distribution?
  3. GATE 2022 ES Q12 (1 mark, Multiple choice) – A normal population yields sample25.8,36.6,26.3,21.8,27.2. Given one-sided t critical value2.132 at 5% significance with 4 degrees of freedom, select…
  4. GATE 2022 ES Q53 (2 marks, Numerical answer) – Emails arrive60% corporate,30% Gmail,5% Yahoo,5% Zoho. Spam fractions are1%,2%,3%,3% respectively, with the same spam filter. Find probability a…
  5. GATE 2023 ES Q30 (1 mark, Numerical answer) – Disease prevalence is .002. A test is positive with probability.98 given disease and .03 given no disease. Find probability of disease given a…
  6. GATE 2023 ES Q36 (2 marks, Multiple choice) – Nine independent normal holding times have mean8.33 and standard deviation4.472. Sample mean M is normal. For the printed hypotheses…
  7. GATE 2024 ES Q11 (1 mark, Multiple choice) – Ten cards are numbered1–10. Find the probability of drawing an even number or a multiple of 5.
  8. GATE 2024 ES Q36 (2 marks, Multiple choice) – Ten observations are drawn from a normal population with mean µ. Their mean is x and standard deviation S. The supplied Student-t table lists rows…
  9. GATE 2025 ES Q24 (1 mark, Multiple select) – Consider (i) Pollutant concentrations are generally modeled as lognormal;(ii) concentrations are generally Poisson;(iii) weekly exceedance frequency…
  10. GATE 2026 ES Q14 (1 mark, Multiple choice) – One card is selected randomly from 26 cards bearing the English alphabet, one distinct letter per card. What is the probability that the letter is E…
  11. GATE 2026 ES Q15 (1 mark, Multiple choice) – Which expression is Pearson’s chi-square statistic? Here O i,E i are observed and expected frequencies,n is the number of observations, O and are the…
  12. GATE 2026 ES Q48 (2 marks, Numerical answer) – PM concentrations at seven locations are 45,40,55,65,60,35,50 µg/m³. Find their standard deviation in µg/m³,to one decimal place.