Multiple choice

Cards marked with numbers 2 to 101 are placed in a box and mixed thoroughly. One card is drawn from the box. The probability that the number on the card is a prime number less than 20 is

  1. 12/25

  2. 8/25

  3. 4/25

  4. 2/25
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The total number of cards marked from 2 to 101 is 100. The prime numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19, which gives a total of 8 favorable outcomes. Therefore, the probability of drawing such a card is 8/100, which simplifies to 2/25.

AI explanation

Using the fundamental principle of counting, the total number of possible cards is 101 minus 2 plus 1, which equals 100. The prime numbers less than 20 in this range are 2, 3, 5, 7, 11, 13, 17 and 19, giving 8 favorable outcomes. The probability is the number of favorable outcomes divided by the total outcomes, which is 8 divided by 100. This simplifies to 2 divided by 25, which is 2/25.

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