Question 1196586
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An urn contains 9 red marbles, 10 white marbles, and 5 blue marbles {{{highlight(cross(marbles))}}}. 
A child randomly selects three (without replacement) from the urn. 
Round to four decimal places. Find the probability all three marbles are the same color
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In all, there are 9 + 10 + 5 = 24 marbles 


The number of all possible triples is  {{{C[24]^3}}} = 2024.

The number of all possible red   triples is  {{{C[9]^3}}} = 84.

The number of all possible white triples is  {{{C[10]^3}}} = 120.

The number of all possible blue triples is  {{{C[5]^3}}} = 10.


The number of all favorable choices is the sum  84 + 120 + 10 = 214.



The probability under the problem's question is  


    P = {{{favorable_triples/total_triples}}} = {{{214/2024}}} = 0.1057  (rounded).    <U>ANSWER</U>
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Solved.