Multiple choice

A bag contains 10 blue and 5 black balls. If two balls are drawn simultaneously and the first ball turns out to be blue, then what is the probability that the second ball is also blue?

  1. 9 14

  2. 3 5

  3. 2 3

  4. 5 7
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A Correct answer
Explanation

Initially there are 10 blue and 5 black balls (total 15). If one blue ball is drawn, 9 blue and 5 black balls remain (total 14). The probability that the second ball is blue is 9/14.

AI explanation

Use the concept of conditional probability to determine the likelihood of the second ball drawn being blue. After the first blue ball is drawn and removed, the bag now contains a total of 14 balls instead of the original 15. Because one blue ball has been taken out, there are exactly 9 blue balls remaining in the bag. Therefore, the probability of drawing a blue ball on the second draw is 9 divided by 14. The answer is 9/14.

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