Algebra.Com's Answer #734541 by ikleyn(52786)![\"\"](\"/images/stars/stars-13.gif\")  
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document.write( "Ten students, A, B,..., are in a class. A committee of three is chosen at random to represent the class. Find the
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document.write( "probability that:\r
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document.write( "Of 10 students of the class, you can form  =  = 120 triples (triplets), in all.\r\n" );
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document.write( "(a) A belongs to the committee; You can form  = 36 such triples, by adding two other of remaining 9\r\n" );
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document.write( " So the probability under the question is  =  = 0.3 = 30%\r\n" );
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document.write( "(b) B belongs to the committee; Same answer (and same solution) as (a).\r\n" );
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document.write( "(c) A and B belong to the committee; You can form only 8 such triples by adding any of remaining 8 students to A and B.\r\n" );
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document.write( " The answer is  =  .\r\n" );
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document.write( "(d) A or B belong to the committee; Add (a) with (b) and subtract (c):\r\n" );
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document.write( "  =  =  =  .\r\n" );
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document.write( "Solved.\r
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