document.write( "Question 1204025: An urn has 21 balls that are identical except that 5 are white, 9 are red, and 7 are blue. What is the probability that all are white if 3 are selected randomly without replacement?
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Algebra.Com's Answer #840006 by ikleyn(52778) $\"\"$ $\"About$

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document.write( "    P =  =  =  = 0.007519...   ANSWER\r\n" );
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document.write( "The denominator is the number of all different sub-sets of 3 elements of the universal set of 21 balls.\r\n" );
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document.write( "The numerator is the number of all different sub-sets of 3 white balls of the set of 5 white balls.\r\n" );
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\n" ); document.write( "\n" ); document.write( "To see many other similar (and different) problems solved, look into the lesson\r
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