Multiple choice

A bag contains 10 white balls and 5 red balls. 3 balls are drawn at random. What is the probability that all of them are red?

  1. 1 22

  2. 3 22

  3. 2 91

  4. 2 77

  5. 3 77
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The probability of drawing three red balls is (5/15) x (4/14) x (3/13). This simplifies to 2/91, matching option C.

AI explanation

The total number of ways to draw 3 balls from the 15 available is calculated using the combination formula 15C3, which equals (15 times 14 times 13) divided by (3 times 2 times 1), or 455 ways. The number of favorable ways to draw 3 red balls from the 5 available is 5C3, which equals 10 ways. The probability is the favorable outcomes divided by the total outcomes, 10 divided by 455, which simplifies to 2/91.

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