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Home Q & A Board Science-Related Homework Help Mathematics
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NVstudent NVstudent
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11 years ago
How do I calculate the following probability

There are a total of 40 balls in a bag. 32 balls are blue. 8 balls are red. If I draw at random three balls, what is the chance that I will draw all three red balls?

So basically three draws: 8 out of 40 and then 7 out of 39 and then 6 out of 38.
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micro01micro01
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11 years ago
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#2
11 years ago
Drawing without replacement.

1st draw   8/40
2nd draw  7/39
3rd draw   6/38
Since draws are independent Pr = (8/40)*(7/39)*(6/38)
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Drawing with replacement Pr = (8*/40)^3
wrote...
#3
11 years ago
I think you answered your question... as long as as you draw each ball you do not put it back in the bag.

(8/40) * (7/39) * (6/38) = 336 / 59280 = 0.0056
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