The GATE Grind

GATE Engineering Mathematics: Probability and Statistics – Previous Year Questions

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

  1. GATE 2017 CS Q29 (1 mark, Numerical answer) – Let X be a Gaussian random variable with mean 0 and variance 2. Let Y = (X, 0) where (a, b) is the maximum of a and b. The median of Y is .
  2. GATE 2016 CS Q14 (1 mark, Numerical answer) – A probability density function on the interval [a, 1] is given by 1/x2 and outside this interval the value of the function is zero. The value of a is…
  3. GATE 2016 CS Q39 (2 marks, Numerical answer) – Consider the following experiment. Step 1. Flip a fair coin twice. Step 2. If the outcomes are (TAILS, HEADS) then output Y and stop. Step 3. If the…
  4. GATE 2018 CS Q25 (1 mark, Numerical answer) – Two people, P and Q, decide to independently roll two identical dice, each with 6 faces, numbered 1 to 6. The person with the lower number wins. In…
  5. GATE 2018 CS Q54 (2 marks, Numerical answer) – Consider Guwahati (G) and Delhi (D) whose temperatures can be classified as high (H), medium (M) and low (L). Let P(H G) denote the probability that…
  6. GATE 2019 CS Q32 (1 mark, Numerical answer) – Two numbers are chosen independently and uniformly at random from the set \1,2,,13\. The probability (rounded off to 3 decimal places) that their…
  7. GATE 2019 CS Q57 (2 marks, Numerical answer) – Suppose Y is distributed uniformly in the open interval (1,6). The probability that the polynomial 3x2+6xY+3Y+6 has only real roots is (rounded off to…
  8. GATE 2026 CS (CS2) Q14 (1 mark, Multiple choice) – The probability density function f(x) of a random variable X is f(x) = 132 (-x218), x (-,+). Which one of the following statements is correct about…
  9. GATE 2026 CS (CS2) Q63 (2 marks, Numerical answer) – Suppose an unbiased coin is tossed 6 times. Each toss is independent. Let E 1 be the event that among the second, fourth, and sixth tosses, there are…
  10. GATE 2026 CS (CS1) Q11 (1 mark, Multiple choice) – An urn contains one red ball and one blue ball. At each step, a ball is picked uniformly at random from the urn, and this ball together with another…
  11. GATE 2026 CS (CS1) Q58 (2 marks, Numerical answer) – Let X be a random variable which takes values in the set \1, 2, 3, 4, 5, 6, 7, 8\. Further, (X = 1) = (X = 2) = (X = 5) = (X = 7) = 16 and (X = 3) =…
  12. GATE 2025 CS (CS2) Q64 (2 marks, Numerical answer) – A quadratic polynomial (x - )(x - ) over complex numbers is said to be square invariant if (x - )(x - ) = (x - 2)(x - 2). Suppose from the set of all…
  13. GATE 2025 CS (CS2) Q65 (2 marks, Numerical answer) – The unit interval (0,1) is divided at a point chosen uniformly distributed over (0,1) in R into two disjoint subintervals. The expected length of the…
  14. GATE 2025 CS (CS1) Q32 (1 mark, Numerical answer) – A box contains 5 coins: 4 regular coins and 1 fake coin. When a regular coin is tossed, the probability P(head) = 0.5 and for a fake coin, P(head) =…
  15. GATE 2025 CS (CS1) Q56 (2 marks, Numerical answer) – Suppose a 5-bit message is transmitted from a source to a destination through a noisy channel. The probability that a bit of the message gets flipped…
  16. GATE 2024 CS (CS2) Q18 (1 mark, Multiple choice) – When six unbiased dice are rolled simultaneously, the probability of getting all distinct numbers (i.e., 1, 2, 3, 4, 5, and 6) is
  17. GATE 2024 CS (CS2) Q44 (2 marks, Multiple choice) – Let x and y be random variables, not necessarily independent, that take real values in the interval [0,1]. Let z=xy and let the mean values of x,y,z…
  18. GATE 2024 CS (CS1) Q14 (1 mark, Multiple choice) – Consider a permutation sampled uniformly at random from the set of all permutations of \1,2,3,,n\ for some n 4. Let X be the event that 1 occurs…
  19. GATE 2024 CS (CS1) Q27 (1 mark, Multiple select) – Let A and B be two events in a probability space with P(A)=0.3, P(B)=0.5, and P(A B)=0.1. Which of the following statements is/are TRUE?
  20. GATE 2024 CS (CS1) Q63 (2 marks, Numerical answer) – A bag contains 10 red balls and 15 blue balls. Two balls are drawn randomly without replacement. Given that the first ball drawn is red, the…
  21. GATE 2023 CS Q53 (2 marks, Multiple select) – Consider a random experiment where two fair coins are tossed. Let A be the event that denotes HEAD on both the throws, B be the event that denotes…
  22. GATE 2021 CS Q28 (1 mark, Numerical answer) – The lifetime of a component of a certain type is a random variable whose probability density function is exponentially distributed with parameter 2.…
  23. GATE 2021 CS Q45 (2 marks, Multiple choice) – Consider the two statements. S 1: There exist random variables X and Y such that (E[(X-E(X))(Y-E(Y))])2 > Var[X]Var[Y] S 2: For all random variables X…
  24. GATE 2021 CS Q64 (2 marks, Numerical answer) – A sender (S) transmits a signal, which can be one of the two kinds: H and L with probabilities 0.1 and 0.9 respectively, to a receiver (R). In the…
  25. GATE 2020 CS Q55 (2 marks, Numerical answer) – For n>2, let a\0,1\n be a non-zero vector. Suppose that x is chosen uniformly at random from \0,1\n. Then, the probability that i=1na ix i is an odd…