Free Probability MCQs with Answers

41 Probability MCQs from Statistics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

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41 questions · page 1 of 3

  • A. P(AorB) =0
  • B. P(AandB)=0
  • C. P(AnorB)=0
  • D. P(AeitherB)=0

Explanation: Mutually exclusive events cannot occur together, so their intersection is empty and P(A and B) equals zero.

Correct answer: P(AandB)=0
  • A. Dependent
  • B. Independent
  • C. Overlapped
  • D. None of These

Explanation: Mutually exclusive events cannot occur together, whereas independent events can occur together without affecting each other, so mutually…

Correct answer: Dependent
  • A. It must have a value between 0 and 1
  • B. It can be reported as a decimal or a fraction
  • C. A value near 0 means that the event is not likely to occur/happens
  • D. It is the collection of several experiment

Explanation: A probability is a numerical measure between 0 and 1 and may be written as a decimal or fraction; a value near 0 indicates an unlikely…

Correct answer: It is the collection of several experiment
  • A. Independent
  • B. Mutually exclusive
  • C. Bayesian
  • D. Empirical

Explanation: The special multiplication rule, P(A∩B) = P(A)P(B), applies when events are independent.

Correct answer: Independent
  • A. 4/36
  • B. 13/36
  • C. 21/36
  • D. 15/36

Explanation: There are 11 outcomes with at least one 4 and 6 outcomes whose sum is 7; 2 outcomes belong to both groups.

Correct answer: 15/36
  • A. Independent
  • B. Mutually Exclusive
  • C. Bayesian
  • D. Empirical

Explanation: If occurrence of one event rules out the occurrence of another, their intersection is empty, so they are mutually exclusive.

Correct answer: Mutually Exclusive
  • A. 5
  • B. 5×5
  • C. 1
  • D. None of these

Explanation: Choosing all 5 objects from 5 gives only one possible selection, so \(\binom{5}{5}=5!/(5!0!)=1\).

Correct answer: 1
  • A. 1.2.3.4,.........
  • B. 1.2.3......(n-2) (n-1) (n)
  • C. n. (n-1) (n-2)..............3.2.1.0
  • D. None of these

Explanation: The product of the first n natural numbers is 1 × 2 × 3 × ⋯ × n, which is written as n!. Option b expresses this product in ascending order.

Correct answer: 1.2.3......(n-2) (n-1) (n)
  • A. 1/3
  • B. 2/3
  • C. 1/2
  • D. 0

Explanation: Let P(T)=p, so P(H)=2p. Since P(H)+P(T)=1, 3p=1 and therefore P(H)=2/3.

Correct answer: 2/3
  • A. 4/5
  • B. 1/20
  • C. 0
  • D. 1/9

Explanation: Using P(A|B)=P(A∩B)/P(B), we get 1/4=(1/5)/P(B). Rearranging gives P(B)=4/5.

Correct answer: 4/5
  • A. 1/4
  • B. 2/4
  • C. 3/4
  • D. 4/4

Explanation: With two fair coins, the four equally likely outcomes are HH, HT, TH, and TT. Three contain at least one head, so the probability is 3/4.

Correct answer: 3/4
  • A. 1/8
  • B. 2/8
  • C. 5/8
  • D. 7/8

Explanation: Only one outcome, tails-tails-tails, gives exactly three tails. With three fair coins there are 2^3 = 8 equally likely outcomes, so the…

Correct answer: 1/8
  • A. 18/36
  • B. 9/36
  • C. 6/36
  • D. 12/36

Explanation: A sum of two dice is odd when one die shows an odd number and the other an even number.

Correct answer: 18/36
  • A. 7/12
  • B. 6/12
  • C. 12/12
  • D. 4/12

Explanation: The probability is favourable outcomes divided by total outcomes. Six white balls out of 12 balls give 6/12, which can also be simplified…

Correct answer: 6/12
  • A. 1/6
  • B. 2/6
  • C. 3/6
  • D. 6/6

Explanation: The even outcomes on a die are 2, 4, and 6, giving three favourable outcomes out of six. Therefore the probability is 3/6, or 1/2.

Correct answer: 3/6
  • A. 13/52
  • B. 12/52
  • C. 16/52
  • D. 3/52

Explanation: Picture cards are jacks, queens, and kings: 3 ranks in each of 4 suits, making 12 cards.

Correct answer: 12/52
  • A. Positive
  • B. Zero
  • C. None of these
  • D. Negative

Explanation: Probability ranges from 0 to 1, so it may be zero but cannot be negative. A negative value has no meaning as an event probability.

Correct answer: Negative
  • A. Appeared
  • B. Exactly
  • C. Space
  • D. Elementary event

Explanation: An elementary event contains exactly one sample point, such as obtaining a six when rolling a die.

Correct answer: Elementary event
  • A. 16
  • B. 24
  • C. 12
  • D. Non of these

Explanation: In a standard 52-card deck, the picture cards are the jacks, queens, and kings in four suits, so there are 3 × 4 = 12.

Correct answer: 12
  • A. Dependent events
  • B. Independent events
  • C. Equally likely events
  • D. Mutually Exclusive events

Explanation: Independent events occur without changing each other’s probabilities, so the occurrence of one does not affect the other.

Correct answer: Independent events

Probability MCQs: common questions

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