SOLUTION: please help me solve this question. In an urn there are 5 blue, 6 red and 4 green balls. Three balls are randomly drawn from the urn without replacement. What is the probability o

Algebra ->  Probability-and-statistics -> SOLUTION: please help me solve this question. In an urn there are 5 blue, 6 red and 4 green balls. Three balls are randomly drawn from the urn without replacement. What is the probability o      Log On


   



Question 417921: please help me solve this question.
In an urn there are 5 blue, 6 red and 4 green balls. Three balls are randomly drawn from the urn without replacement. What is the probability of drawing only two colors from the urn?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In an urn there are 5 blue, 6 red and 4 green balls.
Three balls are randomly drawn from the urn without replacement.
What is the probability of drawing only two colors from the urn?
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There ae 5C3 = 10 all blue
There are 6C3 = 20 all red
There are 4C3 = 4 all green
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There are 5*6*4 = 120 that are all three colors.---
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There are a total of 15C3 = 455 sets of three.
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# of sets with 2 colors = 455-[10+20+4+120] = 455-154 = 301
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P(drawing a set with only 2 colors) = 301/455
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Cheers,
Stan H.
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