document.write( "Question 1075827: What is probability that of three people selected at random at least two were born on the same day. \n" ); document.write( "

Algebra.Com's Answer #690479 by Edwin McCravy(20056) $\"\"$ $\"About$

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document.write( "The complement event is for all of them to have different\r\n" );
document.write( "birthdays.  Suppose they are Tom, Dick and Harry.\r\n" );
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document.write( "So we get the probability that they all have different \r\n" );
document.write( "birthdays.\r\n" );
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document.write( "There are 365 possible birthdays for Tom.\r\n" );
document.write( "That leaves 364 possible birthdays for Dick.\r\n" );
document.write( "That leaves 363 possible birthdays for Harry. \r\n" );
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document.write( "So the number of ways they can all have different birthdays \r\n" );
document.write( "is \r\n" );
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document.write( "The number of ways they can have ANY birthdays, different\r\n" );
document.write( "or not, is \r\n" );
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document.write( "So the probability that all three have different birthdays is\r\n" );
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document.write( "So the probability that at least two have the same birthday\r\n" );
document.write( "is\r\n" );
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document.write( "Edwin

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