document.write( "Question 934889: Two unbiased dice are thrown in the air. Find the probability that the sum of the scores is either perfect or a prime number. \n" ); document.write( "

Algebra.Com's Answer #567991 by AnlytcPhil(1806) $\"\"$ $\"About$

You can put this solution on YOUR website!

\r\n" );
document.write( "Here are all 36 possible rolls. Each sum occurs\r\n" );
document.write( "on the diagonals that slant this way /:\r\n" );
document.write( "\r\n" );
document.write( "(1,1) (1,2) (1,3) (1,4) (1,5) (1,6)\r\n" );
document.write( "\r\n" );
document.write( "(2,1) (2,2) (2,3) (2,4) (2,5) (2,6) \r\n" );
document.write( "\r\n" );
document.write( "(3,1) (3,2) (3,3) (3,4) (3,5) (3,6) \r\n" );
document.write( "\r\n" );
document.write( "(4,1) (4,2) (4,3) (4,4) (4,5) (4,6) \r\n" );
document.write( "\r\n" );
document.write( "(5,1) (5,2) (5,3) (5,4) (5,5) (5,6) \r\n" );
document.write( "\r\n" );
document.write( "(6,1) (6,2) (6,3) (6,4) (6,5) (6,6)\r\n" );
document.write( "\r\n" );
document.write( " P(2)=1/36\r\n" );
document.write( " P(3)=2/36\r\n" );
document.write( " P(4)=3/36\r\n" );
document.write( " P(5)=4/36\r\n" );
document.write( " P(6)=5/36\r\n" );
document.write( " P(7)=6/36\r\n" );
document.write( " P(8)=5/36\r\n" );
document.write( " P(9)=4/36\r\n" );
document.write( "P(10)=3/36\r\n" );
document.write( "P(11)=2/36\r\n" );
document.write( "P(12)=1/36 \r\n" );
document.write( "\r\n" );
document.write( "A perfect number is one equal to the sum of its divisors other \r\n" );
document.write( "than itself. The divisors of 6 other that 6 are 1,2, and 3 and \r\n" );
document.write( "1+2+3=6.\r\n" );
document.write( "\r\n" );
document.write( "[The next perfect number is 28 = 1+2+4+7+14, so 6 is the only\r\n" );
document.write( "perfect number obtainable by throwing two dice.]\r\n" );
document.write( "\r\n" );
document.write( "2,3,5,7,11 are the primes that can be thrown.\r\n" );
document.write( "\r\n" );
document.write( "P(perfect or prime) = P(6)+P(2)+P(3)+P(5)+P(7)+P(11) =  =  = \r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( "

\n" );