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# Probability

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Intern
Joined: 28 Nov 2013
Posts: 5

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28 Nov 2013, 15:12
Dear Expert:

Please, help me out with the following problem;

What is the probability of taking out two green marbles at one time both from a basket with three green marbles, two blue, and 5 red.
The trick is that the two marbles are took out at the same time. Not one after the other.

It looks that the answer is 10/64 or 5/32 but i don´t know how!

Thanks for your help!

Kudos [?]: [0], given: 0

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
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Kudos [?]: 17359 [0], given: 232

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28 Nov 2013, 21:58
UlisesOrdonez wrote:
Dear Expert:

Please, help me out with the following problem;

What is the probability of taking out two green marbles at one time both from a basket with three green marbles, two blue, and 5 red.
The trick is that the two marbles are took out at the same time. Not one after the other.

It looks that the answer is 10/64 or 5/32 but i don´t know how!

Thanks for your help!

Number of ways of selecting two green marbles out of 3 = 3C2 = 3
Number of ways of selecting 2 marbles out of a total of 10 marbles = 10C2 = 45

Probability that the two marbles we pick are green = 3/45 = 1/15
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Kudos [?]: 17359 [0], given: 232

Re: Probability   [#permalink] 28 Nov 2013, 21:58
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# Probability

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