What is the Probability of Selecting a Prime Number Among the First 20 Natural Numbers?

Learn how to calculate the probability of picking a prime number from the first 20 natural numbers, with clear examples and key mathematical insights.

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Among the first 20 natural numbers, 8 are prime: 2, 3, 5, 7, 11, 13, 17, and 19. This means the probability of selecting a prime number randomly from the first 20 natural numbers is 8 out of 20, or 40%.

FAQs & Answers

  1. How do you find the probability of a prime number in a set? To find the probability of a prime number in a set, divide the number of prime numbers in the set by the total numbers in the set. For example, for the first 20 natural numbers, there are 8 primes, so the probability is 8/20 or 40%.
  2. What are prime numbers within the first 20 natural numbers? The prime numbers within the first 20 natural numbers are 2, 3, 5, 7, 11, 13, 17, and 19.
  3. Why is 1 not considered a prime number? 1 is not considered a prime number because prime numbers are defined as natural numbers greater than 1 that have exactly two distinct positive divisors: 1 and themselves.

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