Multiple choice

A bag contains 2 distinct red balls, 5 distinct blue balls, 1 distinct black ball, and 7 distinct green balls. If 2 balls are drawn at random, find the probability that none of the balls is blue.

  1. 19 21

  2. 5 7

  3. 2 3

  4. 3 7
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total balls = 2+5+1+7 = 15. Non-blue balls = 2+1+7 = 10. Probability of picking 2 non-blue balls = (10/15) * (9/14) = (2/3) * (9/14) = 18/42 = 3/7.

AI explanation

There are 15 total balls, so the total number of ways to draw 2 balls is 15 choose 2, which is 105. Since there are 5 blue balls, there are 10 non-blue balls, and the number of ways to draw 2 non-blue balls is 10 choose 2, which is 45. The probability is 45 divided by 105, which simplifies to 3 divided by 7.

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