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There are 5 black balls and 7 red balls in an urn. If 4 balls are drawn without replacement, what is the probability that exactly 2 black balls are drawn? Express your answer as a fraction or a decimal number rounded to four decimal places.

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Answer:

Decimal places

Explanation:

To find the probability of exactly 2 black balls being drawn out of 4 balls without replacement, we need to calculate the probability of selecting 2 black balls and 2 non-black balls.

The total number of balls in the urn is 5 black balls + 7 red balls = 12 balls.

First, let's calculate the probability of selecting 2 black balls out of the 5 black balls in the urn.

The probability of the first ball being black is 5/12.

After selecting a black ball, there are 4 black balls remaining out of 11 total balls.

Therefore, the probability of selecting a second black ball is 4/11.

Next, we need to calculate the probability of selecting 2 non-black balls out of the remaining 7 red balls in the urn.

The probability of the first ball being red is 7/10.

After selecting a red ball, there are 6 red balls remaining out of 9 total balls.

Therefore, the probability of selecting a second red ball is 6/9.

To find the probability of both events happening together (2 black balls and 2 red balls), we multiply the individual probabilities:

(5/12) * (4/11) * (7/10) * (6/9) ≈ 0.0578

Rounded to four decimal places, the probability that exactly 2 black balls are drawn is approximately 0.0578.

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