Multiple choice

A bag contains 4 blue, 5 white and 6 green balls. Two balls are drawn at random. What is the probability that one ball is white?

  1. 10/21

  2. 1/2

  3. 3/4

  4. 2/35
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A Correct answer
Explanation

The total number of ways to draw 2 balls from 15 is 105. The number of ways to draw exactly 1 white ball (and 1 non-white ball) is 5 * 10 = 50. Thus, the probability is 50 / 105, which simplifies to 10/21.

AI explanation

The total number of balls is 4 blue plus 5 white plus 6 green, which equals 15. The number of ways to draw two balls is the combination of 15 taken 2 at a time, which is 15 multiplied by 14 divided by 2, yielding 105. The number of ways to draw exactly one white ball is the combination of 5 taken 1 at a time multiplied by the combination of 10 taken 1 at a time, giving 50. The probability is 50 divided by 105, which simplifies to 10 divided by 21.

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