Question 254461
A bag contains 4 white ball,5 red ball,6 green balls 3 balls are drawns at random.what is the probabilty that a white ,a red ,a green ball are drawn.
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# of possible outcomes: 15C3 = 455 sets of 3 balls
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# of all white = 4C3= 4
# of all red = 5C3 = 10
# of all green = 6C2 = 15
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# of 2W and 1red = (4C2)*5 = 30
# of 2W and 1green= (4C2)*6 = 36
# of 2R and 1W = (5C2)*4 = 40
# of 2R and 1G = (5C2)*6 = 60
# of 2G and 1red = (6C2)*5 = 75
# of 2G and 1W = (6C2)4 = 60
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# of ways to get 1R,1W,1G = 455-[29+226+75] = 125
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P(1R,1W,1G) = 125/455 = 0.2747
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Cheers,
Stan H.