SOLUTION: Hi, Please help, I just don't understand how to achieve the answers to this question. If you can provide the formula and the answer, it will be appreciated. A box contains 5 red

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Question 860790: Hi,
Please help, I just don't understand how to achieve the answers to this question. If you can provide the formula and the answer, it will be appreciated.
A box contains 5 red and 8 green marbles. You reach in and remove 3 marbles all at once.
(a) Find the probability that these 3 marbles are all red. (Enter your answer as a fraction.)
(a) Find the probability that these 3 marbles are all red. (Enter your answer as a fraction.)
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A box contains 5 red and 8 green marbles. You reach in and remove 3 marbles all at once.
(a) Find the probability that these 3 marbles are all red. (Enter your answer as a fraction.)
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# of ways to select 3 red : 5C3 = 5C2 = (5*4)/(1*2) = 10
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# of possible groups of 3:: 13C3 = (13*12*11)/(1*2*3) = 286
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Ans: 10/286 = 0.0350
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Cheers,
Stan H.