Question 93691This question is from textbook
: A number is drawn at random from the numbers 1 through 20. The probability the number is a multiple of 3 is:
A box contains 4 red and 5 green balls. Three balls are drawn. The probability 2 red and 1 green are drawn is:
This question is from textbook
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A number is drawn at random from the numbers 1 through 20. The probability the number is a multiple of 3 is:
Multiples of 3 are 3,6,9,12,15,18
Prob(condition stated) = 6/20 = 3/10
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A box contains 4 red and 5 green balls. Three balls are drawn. The probability 2 red and 1 green are drawn is:
# of ways to get 2 red = 4C2 = 6
# of ways to get 1 green = 5C1 = 5
So # of ways to meet the condition = 6*5 = 30
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# of ways to pick 3 balls with no condition = 9C3 = [9*8*7]/[1*2*3] = 84
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Prob(stated condition) = 30/84 = 15/42 = 5/14
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Cheers,
Stan H.
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