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Because of a mistake in​ packaging, a case of 16 bottles of wine contained 9 of brand A and 7 of brand​ B, each without labels. All the bottles look alike and have an equal probability of being chosen. FiveFive bottles are randomly selected. ​(a) What is the probability that all fivefive are brand​ A? ​(b) What is the probability that exactly twotwo areare brand​ A? ​(c) What is the probability that none is brand​ A?

User Beulah
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2 Answers

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Final answer:

To solve this probability problem, we can use the formula for probability of independent events. For part (a), the probability of selecting all five brand A bottles is (9/16) * (8/15) * (7/14) * (6/13) * (5/12). For part (b), the probability of selecting exactly two brand A bottles is (9/16) * (8/15) * (7/14) * (7/13) * (6/12) * (5/11) * 5C2. For part (c), the probability of selecting none of the brand A bottles is (7/16) * (6/15) * (5/14) * (4/13) * (3/12).

Step-by-step explanation:

To solve this problem, we can use the concept of probability. Let's go through each part of the question:

(a) To calculate the probability that all five bottles are brand A, we need to consider that there are 9 bottles of brand A and a total of 16 bottles. We can use the formula for probability of independent events, which is the number of favorable outcomes divided by the number of possible outcomes. So, the probability would be (9/16) * (8/15) * (7/14) * (6/13) * (5/12).

(b) To calculate the probability that exactly two bottles are brand A, we need to consider that there are 9 bottles of brand A and a total of 16 bottles. We can use the combination formula to calculate the number of ways to choose 2 bottles out of 5 and then multiply it by the probability of selecting brand A bottles and brand B bottles. So, the probability would be (9/16) * (8/15) * (7/14) * (7/13) * (6/12) * (5/11) * 5C2.

(c) To calculate the probability that none of the bottles are brand A, we need to consider that there are 9 bottles of brand A and a total of 16 bottles. We can use the formula for probability of independent events, which is the number of favorable outcomes divided by the number of possible outcomes. So, the probability would be (7/16) * (6/15) * (5/14) * (4/13) * (3/12).

User JohnCand
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2 votes

Answer:

a) 0.0289

b) 0.289

c) 0.0048

Step-by-step explanation:

16 bottles total

9 Brand A

7 Brand B

5 bottles selected

(a) What is the probability that all five are brand​ A?

Total: ₁₆C₅ = 4368

5 bottles brand A

₉C₅ = 126

126/4368 = 0.0289

(b) What is the probability that exactly two are brand​ A?

Total: ₁₆C₅ = 4368

2 of Brand A: ₉C₂ = 36

3 of Brand B: ₇C₃ = 35

As we have 2 of A AND 3 of B = 36*35 = 1260

1260/4368 = 0.289

(c) What is the probability that none is brand​ A?

Total: ₁₆C₅ = 4368

5 of Brand B: ₅C₇ = 21

21/4368 = 0.0048

User Greg Treleaven
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