SOLUTION: An urn contains blue and purple marbles. The number of purple marbles is 3 more than twice the number of blue marbles. If the probability of drawing a blue marble at random is 1/

Question 612869: An urn contains blue and purple marbles. The number of purple marbles is 3 more than twice the number of blue marbles. If the probability of drawing a blue marble at random is 1/4, how many blue marbles are in the urn?
Thanks!
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
An urn contains blue and purple marbles. The number of purple marbles is 3 more than twice the number of blue marbles. If the probability of drawing a blue marble at random is 1/4, how many blue marbles are in the urn?
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Equations:
p = 2b + 3
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b/[b + p] = 1/4
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b/[b + 2b+3] = 1/4
4b = 3b+3
b = 3 (# of blue marbles)
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Solve for "p":
p = 2b + 3
p = 2*3+3 = 9 (# of purple marbles)
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Cheers,
Stan H.
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