document.write( "Question 1049447: suppose two fair dice have been rolled and the sum of their top faces is divisible by 5.
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Algebra.Com's Answer #665056 by Edwin McCravy(20064)\"\" \"About 
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document.write( "We want the conditional probability that the roll is (5,5)\r\n" );
document.write( "given that the sum is divisible by 5, that is, 5 or 10.\r\n" );
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document.write( "We can express that by:\r\n" );
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document.write( "P(two fives | sum divisible by five)\r\n" );
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document.write( "Here are all 36 possible rolls of a pair\r\n" );
document.write( "of dice:\r\n" );
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document.write( "(1,1) (1,2) (1,3) (1,4) (1,5) (1,6)\r\n" );
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document.write( "(2,1) (2,2) (2,3) (2,4) (2,5) (2,6)\r\n" );
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document.write( "(3,1) (3,2) (3,3) (3,4) (3,5) (3,6) \r\n" );
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document.write( "(4,1) (4,2) (4,3) (4,4) (4,5) (4,6) \r\n" );
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document.write( "(5,1) (5,2) (5,3) (5,4) (5,5) (5,6) \r\n" );
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document.write( "(6,1) (6,2) (6,3) (6,4) (6,5) (6,6)\r\n" );
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document.write( "We are given that the sum of their top\r\n" );
document.write( "faces is divisible by 5, so we reduce \r\n" );
document.write( "the sample space to just those with\r\n" );
document.write( "what is given, that their sum is either \r\n" );
document.write( "5 or 10:\r\n" );
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document.write( "                  (1,4) \r\n" );
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document.write( "            (2,3) \r\n" );
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document.write( "      (3,2) \r\n" );
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document.write( "(4,1)                         (4,6) \r\n" );
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document.write( "                        (5,5) \r\n" );
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document.write( "                  (6,4) \r\n" );
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document.write( "There are 7 in the reduced sample space.\r\n" );
document.write( "Only one of those is (5,5).\r\n" );
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document.write( "So the desired conditional probability is 1/7.\r\n" );
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document.write( "Edwin
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