JEE MAIN · MATHEMATICS · PROBABILITY

JEE Main Probability Questions & Solutions

143 solved questions on Probability, ranging from easy to JEE-Advanced-flavour hard. Click any to see the full solution.

22Easy
116Medium
5Hard

All 143 questions

  1. Medium MCQ +4 / -1 PYQ 2022

    Let X be a random variable having binomial distribution B(7, p). If P(X = 3) = 5P(x = 4), then the sum of the mean and the variance of X is :

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  2. Medium MCQ +4 / -1 PYQ 2022

    Let X have a binomial distribution B(n, p) such that the sum and the product of the mean and variance of X are 24 and 128 respectively. If $P(Xn-3)=\frac{k}{2^{n}}$, then k is…

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  3. Medium MCQ +4 / -1 PYQ 2024

    Three urns A, B and C contain 7 red, 5 black; 5 red, 7 black and 6 red, 6 black balls, respectively. One of the urn is selected at random and a ball is drawn from it. If the ball…

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  4. Easy MCQ +4 / -1 PYQ 2022

    If a random variable X follows the Binomial distribution B(5, p) such that P(X = 0) = P(X = 1), then ${{P(X = 2)} \over {P(X = 3)}}$ is equal to :

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  5. Medium MCQ +4 / -1 PYQ 2023

    Let a die be rolled $n$ times. Let the probability of getting odd numbers seven times be equal to the probability of getting odd numbers nine times. If the probability of getting…

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  6. Medium MCQ +4 / -1 PYQ 2022

    Let E1 and E2 be two events such that the conditional probabilities $P({E_1}|{E_2}) = {1 \over 2}$, $P({E_2}|{E_1}) = {3 \over 4}$ and $P({E_1} \cap {E_2}) = {1 \over 8}$. Then :

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  7. Easy MCQ +4 / -1 PYQ 2022

    A random variable X has the following probability distribution : .tg {border-collapse:collapse;border-spacing:0;} .tg…

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  8. Medium MCQ +4 / -1 PYQ 2023

    If an unbiased die, marked with $-2,-1,0,1,2,3$ on its faces, is thrown five times, then the probability that the product of the outcomes is positive, is :

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  9. Medium MCQ +4 / -1 PYQ 2021

    Let a computer program generate only the digits 0 and 1 to form a string of binary numbers with probability of occurrence of 0 at even places be ${1 \over 2}$ and probability of…

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  10. Medium MCQ +4 / -1 PYQ 2023

    If the probability that the random variable $\mathrm{X}$ takes values $x$ is given by $\mathrm{P}(\mathrm{X}=x)=\mathrm{k}(x+1) 3^{-x}, x=0,1,2,3, \ldots$, where $\mathrm{k}$ is a…

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  11. Easy MCQ +4 / -1 PYQ 2021

    When a missile is fired from a ship, the probability that it is intercepted is ${1 \over 3}$ and the probability that the missile hits the target, given that it is not…

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  12. Hard INTEGER +4 / -1 PYQ 2022

    If the probability that a randomly chosen 6-digit number formed by using digits 1 and 8 only is a multiple of 21 is p, then 96 p is equal to _______________.

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  13. Medium MCQ +4 / -1 PYQ 2020

    In a workshop, there are five machines and the probability of any one of them to be out of service on a day is ${{1 \over 4}}$ . If the probability that at most two machines will…

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  14. Easy MCQ +4 / -1 PYQ 2022

    The probability that a relation R from {x, y} to {x, y} is both symmetric and transitive, is equal to :

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  15. Easy INTEGER +4 / -1 PYQ 2021

    The probability distribution of random variable X is given by : .tg {border-collapse:collapse;border-spacing:0;} .tg…

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  16. Easy MCQ +4 / -1 PYQ 2020

    Let A and B be two events such that the probability that exactly one of them occurs is ${2 \over 5}$ and the probability that A or B occurs is ${1 \over 2}$ , then the probability…

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  17. Medium MCQ +4 / -1 PYQ 2022

    A biased die is marked with numbers 2, 4, 8, 16, 32, 32 on its faces and the probability of getting a face with mark n is ${1 \over n}$. If the die is thrown thrice, then the…

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  18. Medium MCQ +4 / -1 PYQ 2020

    An unbiased coin is tossed 5 times. Suppose that a variable X is assigned the value of k when k consecutive heads are obtained for k = 3, 4, 5, otherwise X takes the value -1.…

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  19. Easy MCQ +4 / -1 PYQ 2021

    Each of the persons A and B independently tosses three fair coins. The probability that both of them get the same number of heads is :

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  20. Medium MCQ +4 / -1 PYQ 2022

    If the sum and the product of mean and variance of a binomial distribution are 24 and 128 respectively, then the probability of one or two successes is :

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  21. Medium MCQ +4 / -1 PYQ 2020

    Out of 11 consecutive natural numbers if three numbers are selected at random (without repetition), then the probability that they are in A.P. with positive common difference, is :

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  22. Medium INTEGER +4 / -1 PYQ 2024

    From a lot of 12 items containing 3 defectives, a sample of 5 items is drawn at random. Let the random variable $X$ denote the number of defective items in the sample. Let items…

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  23. Medium INTEGER +4 / -1 PYQ 2024

    From a lot of 10 items, which include 3 defective items, a sample of 5 items is drawn at random. Let the random variable $X$ denote the number of defective items in the sample. If…

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  24. Medium MCQ +4 / -1 PYQ 2024

    An urn contains 6 white and 9 black balls. Two successive draws of 4 balls are made without replacement. The probability, that the first draw gives all white balls and the second…

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  25. Medium MCQ +4 / -1 PYQ 2023

    A bag contains 6 balls. Two balls are drawn from it at random and both are found to be black. The probability that the bag contains at least 5 black balls is :

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  26. Medium INTEGER +4 / -1 PYQ 2021

    Let Bi (i = 1, 2, 3) be three independent events in a sample space. The probability that only B1 occur is $\alpha$, only B2 occurs is $\beta$ and only B3 occurs is $\gamma$. Let p…

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  27. Medium MCQ +4 / -1 PYQ 2020

    Let A and B be two independent events such that P(A) = ${1 \over 3}$ and P(B) = ${1 \over 6}$. Then, which of the following is TRUE?

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  28. Medium MCQ +4 / -1 PYQ 2021

    Let A denote the event that a 6-digit integer formed by 0, 1, 2, 3, 4, 5, 6 without repetitions, be divisible by 3. Then probability of event A is equal to :

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  29. Medium MCQ +4 / -1 PYQ 2020

    The probability that a randomly chosen 5-digit number is made from exactly two digits is :

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  30. Medium MCQ +4 / -1 PYQ 2021

    An ordinary dice is rolled for a certain number of times. If the probability of getting an odd number 2 times is equal to the probability of getting an even number 3 times, then…

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  31. Medium INTEGER +4 / -1 PYQ 2024

    Let $\mathrm{a}, \mathrm{b}$ and $\mathrm{c}$ denote the outcome of three independent rolls of a fair tetrahedral die, whose four faces are marked $1,2,3,4$. If the probability…

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  32. Easy MCQ +4 / -1 PYQ 2024

    If an unbiased dice is rolled thrice, then the probability of getting a greater number in the $i^{\text {th }}$ roll than the number obtained in the $(i-1)^{\text {th }}$ roll,…

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  33. Medium MCQ +4 / -1 PYQ 2023

    In a bolt factory, machines $A, B$ and $C$ manufacture respectively $20 \%, 30 \%$ and $50 \%$ of the total bolts. Of their output 3, 4 and 2 percent are respectively defective…

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  34. Medium INTEGER +4 / -1 PYQ 2022

    Let S = {E1, E2, ........., E8} be a sample space of a random experiment such that $P({E_n}) = {n \over {36}}$ for every n = 1, 2, ........, 8. Then the number of elements in the…

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  35. Medium INTEGER +4 / -1 PYQ 2021

    An electric instrument consists of two units. Each unit must function independently for the instrument to operate. The probability that the first unit functions is 0.9 and that of…

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  36. Medium MCQ +4 / -1 PYQ 2021

    The coefficients a, b and c of the quadratic equation, ax2 + bx + c = 0 are obtained by throwing a dice three times. The probability that this equation has equal roots is :

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  37. Medium MCQ +4 / -1 PYQ 2021

    When a certain biased die is rolled, a particular face occurs with probability ${1 \over 6} - x$ and its opposite face occurs with probability ${1 \over 6} + x$. All other faces…

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  38. Medium MCQ +4 / -1 PYQ 2025

    One die has two faces marked 1 , two faces marked 2 , one face marked 3 and one face marked 4 . Another die has one face marked 1 , two faces marked 2 , two faces marked 3 and one…

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  39. Medium MCQ +4 / -1 PYQ 2021

    The probability of selecting integers a$\in$[$-$ 5, 30] such that x2 + 2(a + 4)x $-$ 5a + 64 > 0, for all x$\in$R, is :

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  40. Easy INTEGER +4 / -1 PYQ 2022

    A bag contains 4 white and 6 black balls. Three balls are drawn at random from the bag. Let $\mathrm{X}$ be the number of white balls, among the drawn balls. If $\sigma^{2}$ is…

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  41. Medium MCQ +4 / -1 PYQ 2024

    If the mean of the following probability distribution of a radam variable $\mathrm{X}$ : .tg {border-collapse:collapse;border-spacing:0;} .tg…

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  42. Medium MCQ +4 / -1 PYQ 2022

    Let $\mathrm{E}_{1}, \mathrm{E}_{2}, \mathrm{E}_{3}$ be three mutually exclusive events such that $$\mathrm{P}\left(\mathrm{E}_{1}\right)=\frac{2+3 \mathrm{p}}{6},…

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  43. Easy MCQ +4 / -1 PYQ 2020

    A random variable X has the following probability distribution : .tg {border-collapse:collapse;border-spacing:0;width:100%} .tg td{font-family:Arial,…

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  44. Medium MCQ +4 / -1 PYQ 2022

    Bag I contains 3 red, 4 black and 3 white balls and Bag II contains 2 red, 5 black and 2 white balls. One ball is transferred from Bag I to Bag II and then a ball is drawn from…

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  45. Easy MCQ +4 / -1 PYQ 2021

    Words with or without meaning are to be formed using all the letters of the word EXAMINATION. The probability that the letter M appears at the fourth position in any such word is :

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  46. Medium MCQ +4 / -1 PYQ 2021

    Let A be a set of all 4-digit natural numbers whose exactly one digit is 7. Then the probability that a randomly chosen element of A leaves remainder 2 when divided by 5 is :

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  47. Medium MCQ +4 / -1 PYQ 2022

    Five numbers ${x_1},{x_2},{x_3},{x_4},{x_5}$ are randomly selected from the numbers 1, 2, 3, ......., 18 and are arranged in the increasing order $({x_1}

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  48. Hard MCQ +4 / -1 PYQ 2023

    Fifteen football players of a club-team are given 15 T-shirts with their names written on the backside. If the players pick up the T-shirts randomly, then the probability that at…

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  49. Hard INTEGER +4 / -1 PYQ 2023

    A fair $n(n 1)$ faces die is rolled repeatedly until a number less than $n$ appears. If the mean of the number of tosses required is $\frac{n}{9}$, then $n$ is equal to…

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  50. Medium MCQ +4 / -1 PYQ 2024

    The coefficients $\mathrm{a}, \mathrm{b}, \mathrm{c}$ in the quadratic equation $\mathrm{a} x^2+\mathrm{bx}+\mathrm{c}=0$ are from the set $\{1,2,3,4,5,6\}$. If the probability of…

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  51. Medium MCQ +4 / -1 PYQ 2021

    A pack of cards has one card missing. Two cards are drawn randomly and are found to be spades. The probability that the missing card is not a spade, is :

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  52. Medium MCQ +4 / -1 PYQ 2020

    The probabilities of three events A, B and C are given by P(A) = 0.6, P(B) = 0.4 and P(C) = 0.5. If P(A$\cup$B) = 0.8, P(A$\cap$C) = 0.3, P(A$\cap$B$\cap$C) = 0.2, P(B$\cap$C) =…

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  53. Medium MCQ +4 / -1 PYQ 2022

    If a random variable X follows the Binomial distribution B(33, p) such that $3P(X = 0) = P(X = 1)$, then the value of ${{P(X = 15)} \over {P(X = 18)}} - {{P(X = 16)} \over {P(X =…

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  54. Easy MCQ +4 / -1 PYQ 2024

    A coin is biased so that a head is twice as likely to occur as a tail. If the coin is tossed 3 times, then the probability of getting two tails and one head is

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  55. Medium MCQ +4 / -1 PYQ 2022

    Let $S=\{1,2,3, \ldots, 2022\}$. Then the probability, that a randomly chosen number n from the set S such that $\mathrm{HCF}\,(\mathrm{n}, 2022)=1$, is :

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  56. Medium MCQ +4 / -1 PYQ 2022

    Let $S$ be the sample space of all five digit numbers. It $p$ is the probability that a randomly selected number from $S$, is a multiple of 7 but not divisible by 5 , then $9 p$…

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  57. Medium MCQ +4 / -1 PYQ 2021

    Let X be a random variable such that the probability function of a distribution is given by $P(X = 0) = {1 \over 2},P(X = j) = {1 \over {{3^j}}}(j = 1,2,3,...,\infty )$. Then the…

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  58. Medium INTEGER +4 / -1 PYQ 2022

    In an examination, there are 10 true-false type questions. Out of 10, a student can guess the answer of 4 questions correctly with probability ${3 \over 4}$ and the remaining 6…

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  59. Medium MCQ +4 / -1 PYQ 2022

    Out of $60 \%$ female and $40 \%$ male candidates appearing in an exam, $60 \%$ candidates qualify it. The number of females qualifying the exam is twice the number of males…

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  60. Easy MCQ +4 / -1 PYQ 2024

    There are three bags $X, Y$ and $Z$. Bag $X$ contains 5 one-rupee coins and 4 five-rupee coins; Bag $Y$ contains 4 one-rupee coins and 5 five-rupee coins and Bag $Z$ contains 3…

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  61. Medium MCQ +4 / -1 PYQ 2020

    If 10 different balls are to be placed in 4 distinct boxes at random, then the probability that two of these boxes contain exactly 2 and 3 balls is :

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  62. Easy MCQ +4 / -1 PYQ 2023

    Three dice are rolled. If the probability of getting different numbers on the three dice is $\frac{p}{q}$, where $p$ and $q$ are co-prime, then $q-p$ is equal to :

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  63. Medium MCQ +4 / -1 PYQ 2023

    Let $$S=\left\{M=\left[a_{i j}\right], a_{i j} \in\{0,1,2\}, 1 \leq i, j \leq 2\right\}$$ be a sample space and $A=\{M \in S: M$ is invertible $\}$ be an event. Then $P(A)$ is…

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  64. Hard INTEGER +4 / -1 PYQ 2025

    Three distinct numbers are selected randomly from the set $\{1,2,3, \ldots, 40\}$. If the probability, that the selected numbers are in an increasing G.P., is $\frac{m}{n},…

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  65. Medium MCQ +4 / -1 PYQ 2021

    In a group of 400 people, 160 are smokers and non-vegetarian; 100 are smokers and vegetarian and the remaining 140 are non-smokers and vegetarian. Their chances of getting a…

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  66. Medium MCQ +4 / -1 PYQ 2022

    A six faced die is biased such that $3 \times \mathrm{P}($a prime number$)\,=6 \times \mathrm{P}($a composite number$)\,=2 \times \mathrm{P}(1)$. Let X be a random variable that…

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  67. Medium MCQ +4 / -1 PYQ 2024

    An integer is chosen at random from the integers $1,2,3, \ldots, 50$. The probability that the chosen integer is a multiple of atleast one of 4, 6 and 7 is

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  68. Easy INTEGER +4 / -1 PYQ 2020

    The probability of a man hitting a target is ${1 \over {10}}$. The least number of shots required, so that the probability of his hitting the target at least once is greater than…

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  69. Medium MCQ +4 / -1 PYQ 2021

    Let A, B and C be three events such that the probability that exactly one of A and B occurs is (1 $-$ k), the probability that exactly one of B and C occurs is (1 $-$ 2k), the…

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  70. Medium MCQ +4 / -1 PYQ 2022

    Let $X$ be a binomially distributed random variable with mean 4 and variance $\frac{4}{3}$. Then, $54 \,P(X \leq 2)$ is equal to :

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  71. Medium MCQ +4 / -1 PYQ 2021

    A fair coin is tossed a fixed number of times. If the probability of getting 7 heads is equal to probability of getting 9 heads, then the probability of getting 2 heads is :

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  72. Medium MCQ +4 / -1 PYQ 2024

    A fair die is thrown until 2 appears. Then the probability, that 2 appears in even number of throws, is

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  73. Medium MCQ +4 / -1 PYQ 2023

    Let M be the maximum value of the product of two positive integers when their sum is 66. Let the sample space $S = \left\{ {x \in \mathbb{Z}:x(66 - x) \ge {5 \over 9}M} \right\}$…

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  74. Medium MCQ +4 / -1 PYQ 2021

    A fair die is tossed until six is obtained on it. Let x be the number of required tosses, then the conditional probability P(x $\ge$ 5 | x > 2) is :

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  75. Medium MCQ +4 / -1 PYQ 2021

    The probability that two randomly selected subsets of the set {1, 2, 3, 4, 5} have exactly two elements in their intersection, is :

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  76. Medium MCQ +4 / -1 PYQ 2023

    Let N denote the sum of the numbers obtained when two dice are rolled. If the probability that ${2^N}

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  77. Medium MCQ +4 / -1 PYQ 2024

    If three letters can be posted to any one of the 5 different addresses, then the probability that the three letters are posted to exactly two addresses is :

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  78. Medium MCQ +4 / -1 PYQ 2025

    A bag contains 19 unbiased coins and one coin with head on both sides. One coin drawn at random is tossed and head turns up. If the probability that the drawn coin was unbiased,…

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  79. Medium MCQ +4 / -1 PYQ 2023

    A bag contains 6 white and 4 black balls. A die is rolled once and the number of balls equal to the number obtained on the die are drawn from the bag at random. The probability…

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  80. Medium INTEGER +4 / -1 PYQ 2024

    In a tournament, a team plays 10 matches with probabilities of winning and losing each match as $\frac{1}{3}$ and $\frac{2}{3}$ respectively. Let $x$ be the number of matches that…

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  81. Medium MCQ +4 / -1 PYQ 2025

    Let $\mathrm{A}=\left[\mathrm{a}_{\mathrm{ij}}\right]$ be a square matrix of order 2 with entries either 0 or 1 . Let E be the event that A is an invertible matrix. Then the…

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  82. Medium MCQ +4 / -1 PYQ 2021

    Let A and B be independent events such that P(A) = p, P(B) = 2p. The largest value of p, for which P (exactly one of A, B occurs) = ${5 \over 9}$, is :

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  83. Medium MCQ +4 / -1 PYQ 2023

    Let N be the sum of the numbers appeared when two fair dice are rolled and let the probability that $N-2,\sqrt{3N},N+2$ are in geometric progression be $\frac{k}{48}$. Then the…

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  84. Medium MCQ +4 / -1 PYQ 2025

    Let S be the set of all the words that can be formed by arranging all the letters of the word GARDEN. From the set S, one word is selected at random. The probability that the…

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  85. Medium MCQ +4 / -1 PYQ 2021

    Let 9 distinct balls be distributed among 4 boxes, B1, B2, B3 and B4. If the probability than B3 contains exactly 3 balls is $k{\left( {{3 \over 4}} \right)^9}$ then k lies in the…

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  86. Medium INTEGER +4 / -1 PYQ 2021

    Let X be a random variable with distribution. .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial,…

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  87. Medium MCQ +4 / -1 PYQ 2021

    The probability that a randomly selected 2-digit number belongs to the set {n $\in$ N : (2n $-$ 2) is a multiple of 3} is equal to :

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  88. Medium MCQ +4 / -1 PYQ 2020

    A dice is thrown two times and the sum of the scores appearing on the die is observed to be a multiple of 4. Then the conditional probability that the score 4 has appeared atleast…

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  89. Medium MCQ +4 / -1 PYQ 2021

    A student appeared in an examination consisting of 8 true-false type questions. The student guesses the answers with equal probability. the smallest value of n, so that the…

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  90. Medium MCQ +4 / -1 PYQ 2021

    Two fair dice are thrown. The numbers on them are taken as $\lambda$ and $\mu$, and a system of linear equationsx + y + z = 5x + 2y + 3z = $\mu$ x + 3y + $\lambda$z = 1is…

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  91. Medium INTEGER +4 / -1 PYQ 2020

    In a bombing attack, there is 50% chance that a bomb will hit the target. Atleast two independent hits are required to destroy the target completely. Then the minimum number of…

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  92. Medium INTEGER +4 / -1 PYQ 2021

    Let there be three independent events E1, E2 and E3. The probability that only E1 occurs is $\alpha$, only E2 occurs is $\beta$ and only E3 occurs is $\gamma$. Let 'p' denote the…

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  93. Medium MCQ +4 / -1 PYQ 2020

    In a box, there are 20 cards, out of which 10 are lebelled as A and the remaining 10 are labelled as B. Cards are drawn at random, one after the other and with replacement, till a…

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  94. Medium MCQ +4 / -1 PYQ 2022

    Let $\mathrm{A}$ and $\mathrm{B}$ be two events such that $P(B \mid A)=\frac{2}{5}, P(A \mid B)=\frac{1}{7}$ and $P(A \cap B)=\frac{1}{9} \cdot$ Consider (S1) $P\left(A^{\prime}…

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  95. Medium MCQ +4 / -1 PYQ 2022

    The probability that a randomly chosen one-one function from the set {a, b, c, d} to the set {1, 2, 3, 4, 5} satisfies f(a) + 2f(b) $-$ f(c) = f(d) is :

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  96. Medium MCQ +4 / -1 PYQ 2021

    Let in a Binomial distribution, consisting of 5 independent trials, probabilities of exactly 1 and 2 successes be 0.4096 and 0.2048 respectively. Then the probability of getting…

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  97. Medium MCQ +4 / -1 PYQ 2022

    The mean and variance of a binomial distribution are $\alpha$ and $\frac{\alpha}{3}$ respectively. If $\mathrm{P}(X=1)=\frac{4}{243}$, then $\mathrm{P}(X=4$ or 5$)$ is equal to :

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  98. Medium MCQ +4 / -1 PYQ 2023

    Let N denote the number that turns up when a fair die is rolled. If the probability that the system of equations $x + y + z = 1$ $2x + \mathrm{N}y + 2z = 2$ $3x + 3y + \mathrm{N}z…

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  99. Medium MCQ +4 / -1 PYQ 2023

    The random variable $\mathrm{X}$ follows binomial distribution $\mathrm{B}(\mathrm{n}, \mathrm{p})$, for which the difference of the mean and the variance is 1 . If $2…

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  100. Medium MCQ +4 / -1 PYQ 2022

    If the numbers appeared on the two throws of a fair six faced die are $\alpha$ and $\beta$, then the probability that $x^{2}+\alpha x+\beta0$, for all $x \in \mathbf{R}$, is :

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  101. Medium MCQ +4 / -1 PYQ 2024

    Three rotten apples are accidently mixed with fifteen good apples. Assuming the random variable $x$ to be the number of rotten apples in a draw of two apples, the variance of $x$…

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  102. Hard MCQ +4 / -1 PYQ 2021

    Four dice are thrown simultaneously and the numbers shown on these dice are recorded in 2 $\times$ 2 matrices. The probability that such formed matrix have all different entries…

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  103. Easy MCQ +4 / -1 PYQ 2024

    Two integers $x$ and $y$ are chosen with replacement from the set $\{0,1,2,3, \ldots, 10\}$. Then the probability that $|x-y|5$, is :

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  104. Medium MCQ +4 / -1 PYQ 2023

    Two dice A and B are rolled. Let the numbers obtained on A and B be $\alpha$ and $\beta$ respectively. If the variance of $\alpha-\beta$ is $\frac{p}{q}$, where $p$ and $q$ are…

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  105. Medium MCQ +4 / -1 PYQ 2023

    In a binomial distribution $B(n,p)$, the sum and the product of the mean and the variance are 5 and 6 respectively, then $6(n+p-q)$ is equal to :

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  106. Medium INTEGER +4 / -1 PYQ 2023

    A bag contains six balls of different colours. Two balls are drawn in succession with replacement. The probability that both the balls are of the same colour is p. Next four balls…

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  107. Medium MCQ +4 / -1 PYQ 2023

    Two dice are thrown independently. Let $\mathrm{A}$ be the event that the number appeared on the $1^{\text {st }}$ die is less than the number appeared on the $2^{\text {nd }}$…

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  108. Medium MCQ +4 / -1 PYQ 2023

    Let $\mathrm{S} = \{ {w_1},{w_2},......\}$ be the sample space associated to a random experiment. Let $P({w_n}) = {{P({w_{n - 1}})} \over 2},n \ge 2$. Let $A = \{ 2k + 3l:k,l \in…

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  109. Medium INTEGER +4 / -1 PYQ 2022

    The sum and product of the mean and variance of a binomial distribution are 82.5 and 1350 respectively. Then the number of trials in the binomial distribution is ____________.

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  110. Medium MCQ +4 / -1 PYQ 2020

    Let EC denote the complement of an event E. Let E1 , E2 and E3 be any pairwise independent events with P(E1) > 0 and P(E1 $\cap$ E2 $\cap$ E3) = 0. Then P($E_2^C \cap…

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  111. Medium MCQ +4 / -1 PYQ 2022

    The probability that a randomly chosen 2 $\times$ 2 matrix with all the entries from the set of first 10 primes, is singular, is equal to :

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  112. Medium MCQ +4 / -1 PYQ 2020

    In a game two players A and B take turns in throwing a pair of fair dice starting with player A and total of scores on the two dice, in each throw is noted. A wins the game if he…

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  113. Medium MCQ +4 / -1 PYQ 2024

    The coefficients $a, b, c$ in the quadratic equation $a x^2+b x+c=0$ are chosen from the set $\{1,2,3,4,5,6,7,8\}$. The probability of this equation having repeated roots is :

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  114. Medium INTEGER +4 / -1 PYQ 2023

    25% of the population are smokers. A smoker has 27 times more chances to develop lung cancer than a non smoker. A person is diagnosed with lung cancer and the probability that…

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  115. Medium MCQ +4 / -1 PYQ 2023

    Let $\Omega$ be the sample space and $\mathrm{A \subseteq \Omega}$ be an event. Given below are two statements : (S1) : If P(A) = 0, then A = $\phi$ (S2) : If P(A) = 1, then A =…

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  116. Easy MCQ +4 / -1 PYQ 2021

    Two dies are rolled. If both dices have six faces numbered 1, 2, 3, 5, 7 and 11, then the probability that the sum of the numbers on the top faces is less than or equal to 8 is :

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  117. Easy MCQ +4 / -1 PYQ 2021

    Let S = {1, 2, 3, 4, 5, 6}. Then the probability that a randomly chosen onto function g from S to S satisfies g(3) = 2g(1) is :

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  118. Medium MCQ +4 / -1 PYQ 2022

    Let a biased coin be tossed 5 times. If the probability of getting 4 heads is equal to the probability of getting 5 heads, then the probability of getting atmost two heads is :

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  119. Medium INTEGER +4 / -1 PYQ 2023

    Let the probability of getting head for a biased coin be $\frac{1}{4}$. It is tossed repeatedly until a head appears. Let $\mathrm{N}$ be the number of tosses required. If the…

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  120. Easy MCQ +4 / -1 PYQ 2024

    Two marbles are drawn in succession from a box containing 10 red, 30 white, 20 blue and 15 orange marbles, with replacement being made after each drawing. Then the probability,…

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  121. Medium INTEGER +4 / -1 PYQ 2024

    Three balls are drawn at random from a bag containing 5 blue and 4 yellow balls. Let the random variables $X$ and $Y$ respectively denote the number of blue and yellow balls. If…

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  122. Easy INTEGER +4 / -1 PYQ 2021

    A fair coin is tossed n-times such that the probability of getting at least one head is at least 0.9. Then the minimum value of n is ______________.

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  123. Medium MCQ +4 / -1 PYQ 2023

    A pair of dice is thrown 5 times. For each throw, a total of 5 is considered a success. If the probability of at least 4 successes is $\frac{k}{3^{11}}$, then $k$ is equal to :

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  124. Medium MCQ +4 / -1 PYQ 2023

    A coin is biased so that the head is 3 times as likely to occur as tail. This coin is tossed until a head or three tails occur. If $\mathrm{X}$ denotes the number of tosses of the…

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  125. Medium MCQ +4 / -1 PYQ 2020

    Box I contains 30 cards numbered 1 to 30 and Box II contains 20 cards numbered 31 to 50. A box is selected at random and a card is drawn from it. The number on the card is found…

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  126. Easy MCQ +4 / -1 PYQ 2024

    A company has two plants $A$ and $B$ to manufacture motorcycles. $60 \%$ motorcycles are manufactured at plant $A$ and the remaining are manufactured at plant $B .80 \%$ of the…

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  127. Medium INTEGER +4 / -1 PYQ 2024

    A fair die is tossed repeatedly until a six is obtained. Let $X$ denote the number of tosses required and let $a=P(X=3), b=P(X \geqslant 3)$ and $c=P(X \geqslant 6 \mid X3)$. Then…

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  128. Medium INTEGER +4 / -1 PYQ 2025

    A card from a pack of 52 cards is lost. From the remaining 51 cards, n cards are drawn and are found to be spades. If the probability of the lost card to be a spade is…

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  129. Medium MCQ +4 / -1 PYQ 2024

    A bag contains 8 balls, whose colours are either white or black. 4 balls are drawn at random without replacement and it was found that 2 balls are white and other 2 balls are…

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  130. Easy MCQ +4 / -1 PYQ 2024

    Let Ajay will not appear in JEE exam with probability $\mathrm{p}=\frac{2}{7}$, while both Ajay and Vijay will appear in the exam with probability $\mathrm{q}=\frac{1}{5}$. Then…

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  131. Medium MCQ +4 / -1 PYQ 2025

    Two balls are selected at random one by one without replacement from a bag containing 4 white and 6 black balls. If the probability that the first selected ball is black, given…

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  132. Medium MCQ +4 / -1 PYQ 2025

    A coin is tossed three times. Let $X$ denote the number of times a tail follows a head. If $\mu$ and $\sigma^2$ denote the mean and variance of $X$, then the value of…

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  133. Medium MCQ +4 / -1 PYQ 2025

    If $A$ and $B$ are two events such that $P(A \cap B)=0.1$, and $P(A \mid B)$ and $P(B \mid A)$ are the roots of the equation $12 x^2-7 x+1=0$, then the value of $\frac{P(\bar{A}…

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  134. Medium MCQ +4 / -1 PYQ 2025

    $A$ and $B$ alternately throw a pair of dice. A wins if he throws a sum of 5 before $B$ throws a sum of 8 , and $B$ wins if he throws a sum of 8 before $A$ throws a sum of 5 . The…

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  135. Medium MCQ +4 / -1 PYQ 2025

    Two number $\mathrm{k}_1$ and $\mathrm{k}_2$ are randomly chosen from the set of natural numbers. Then, the probability that the value of…

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  136. Medium MCQ +4 / -1 PYQ 2025

    Bag $B_1$ contains 6 white and 4 blue balls, Bag $B_2$ contains 4 white and 6 blue balls, and Bag $B_3$ contains 5 white and 5 blue balls. One of the bags is selected at random…

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  137. Medium MCQ +4 / -1 PYQ 2025

    Bag 1 contains 4 white balls and 5 black balls, and Bag 2 contains n white balls and 3 black balls. One ball is drawn randomly from Bag 1 and transferred to Bag 2. A ball is then…

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  138. Medium MCQ +4 / -1 PYQ 2025

    $$ \text { Given three indentical bags each containing } 10 \text { balls, whose colours are as follows : } $$ $$ \begin{array}{lccc} & \text { Red } & \text { Blue } & \text {…

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  139. Medium MCQ +4 / -1 PYQ 2025

    If the probability that the random variable $X$ takes the value $x$ is given by $P(X=x)=k(x+1) 3^{-x}, x=0,1,2,3 \ldots$, where $k$ is a constant, then $P(X \geq 3)$ is equal to

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  140. Medium MCQ +4 / -1 PYQ 2025

    A box contains 10 pens of which 3 are defective. A sample of 2 pens is drawn at random and let $X$ denote the number of defective pens. Then the variance of $X$ is

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  141. Medium MCQ +4 / -1 PYQ 2025

    The probability, of forming a 12 persons committee from 4 engineers, 2 doctors and 10 professors containing at least 3 engineers and at least 1 doctor, is

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  142. Medium MCQ +4 / -1 PYQ 2025

    Let a random variable X take values 0, 1, 2, 3 with P(X=0)=P(X=1)=p, P(X=2)=P(X=3) and E(X2)=2E(X). Then the value of 8p−1 is :

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  143. Medium MCQ +4 / -1 PYQ 2025

    If A and B are two events such that $P(A) = 0.7$, $P(B) = 0.4$ and $P(A \cap \overline{B}) = 0.5$, where $\overline{B}$ denotes the complement of B, then $P\left(B \mid (A \cup…

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