A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If four marbles are picked at random, what is the probability that none is blue?
Correct answer: B. 33/91
- A. 17/91
- B. 33/91
- C. 51/91
- D. 65/91Islamic Studies Quiz
Explanation
There are 12 non-blue marbles, so the favorable selections are C(12,4) = 495. The total selections are C(15,4) = 1365, giving 495/1365 = 33/91. Students often choose 17/91 by subtracting the number of blue marbles incorrectly instead of using combinations.
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