Probability

This quiz is designed to test your understanding of probability, a branch of mathematics that deals with the likelihood of events occurring.

15 Questions Published

Questions

Question 1 Multiple Choice (Single Answer)

A fair coin is tossed twice. What is the probability of getting two heads?

  1. 1/2
  2. 1/4
  3. 1/8
  4. 1/16
Question 2 Multiple Choice (Single Answer)

A bag contains 5 red balls, 3 blue balls, and 2 green balls. What is the probability of randomly selecting a blue ball?

  1. 5/10
  2. 3/10
  3. 2/10
  4. 1/10
Question 3 Multiple Choice (Single Answer)

A random variable X has a probability distribution given by P(X = x) = k * x^2, where k is a constant and x = 1, 2, 3. Find the value of k.

  1. 1/6
  2. 1/3
  3. 1/2
  4. 2/3
Question 4 Multiple Choice (Single Answer)

Two events A and B are independent. If P(A) = 0.4 and P(B) = 0.6, what is the probability of both A and B occurring?

  1. 0.24
  2. 0.16
  3. 0.12
  4. 0.08
Question 5 Multiple Choice (Single Answer)

A box contains 10 defective items and 90 non-defective items. If two items are randomly selected without replacement, what is the probability that both items are defective?

  1. 1/100
  2. 1/50
  3. 1/25
  4. 1/10
Question 6 Multiple Choice (Single Answer)

A survey found that 60% of people prefer coffee, 30% prefer tea, and 10% prefer both coffee and tea. What is the probability that a randomly selected person prefers coffee or tea?

  1. 0.8
  2. 0.9
  3. 0.7
  4. 0.6
Question 7 Multiple Choice (Single Answer)

A continuous random variable X has a probability density function given by f(x) = 2x for 0 ≤ x ≤ 1. Find the probability that X is less than or equal to 0.5.

  1. 0.25
  2. 0.5
  3. 0.75
  4. 1
Question 8 Multiple Choice (Single Answer)

A random variable X follows a normal distribution with mean μ = 10 and standard deviation σ = 2. What is the probability that X is between 6 and 14?

  1. 0.6827
  2. 0.9545
  3. 0.3173
  4. 0.0455
Question 9 Multiple Choice (Single Answer)

A company claims that their new product will last for at least 100 hours. A consumer group tests the product and finds that the average lifetime is 95 hours with a standard deviation of 10 hours. Assuming the lifetime follows a normal distribution, what is the probability that a randomly selected product will last for more than 100 hours?

  1. 0.1587
  2. 0.8413
  3. 0.3413
  4. 0.6587
Question 10 Multiple Choice (Single Answer)

A bag contains 4 red balls, 3 blue balls, and 2 green balls. If two balls are randomly selected without replacement, what is the probability that the first ball is red and the second ball is blue?

  1. 3/14
  2. 6/35
  3. 2/21
  4. 1/10
Question 11 Multiple Choice (Single Answer)

A fair six-sided die is rolled twice. What is the probability of getting a sum of 7?

  1. 1/6
  2. 1/12
  3. 1/18
  4. 1/24
Question 12 Multiple Choice (Single Answer)

A survey found that 40% of people prefer coffee, 30% prefer tea, and 20% prefer both coffee and tea. What is the probability that a randomly selected person prefers only coffee?

  1. 0.2
  2. 0.3
  3. 0.4
  4. 0.5
Question 13 Multiple Choice (Single Answer)

A random variable X has a probability mass function given by P(X = x) = 1/6 for x = 1, 2, 3, 4, 5, 6. Find the expected value of X.

  1. 3.5
  2. 4
  3. 4.5
  4. 5
Question 14 Multiple Choice (Single Answer)

A continuous random variable X has a probability density function given by f(x) = 3x^2 for 0 ≤ x ≤ 1. Find the variance of X.

  1. 0.25
  2. 0.5
  3. 0.75
  4. 1
Question 15 Multiple Choice (Single Answer)

A company claims that their new product will last for at least 100 hours. A consumer group tests the product and finds that the average lifetime is 95 hours with a standard deviation of 10 hours. Assuming the lifetime follows a normal distribution, what is the probability that a randomly selected product will last for less than 80 hours?

  1. 0.0228
  2. 0.1587
  3. 0.3413
  4. 0.8413

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Probability (1860 questions)