document.write( "Question 143040: A bag contains 15 billiard balls, numbers consecutively from 1 to 15. Six balls are selected at random. What is the probability that the sum of the numbers on the billiard balls will be odd? \n" ); document.write( "
Algebra.Com's Answer #104095 by edjones(8007)\"\" \"About 
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8 are odd, 7 are even.
\n" ); document.write( "All the possible combinations are:
\n" ); document.write( "8C6=28 [all odd]
\n" ); document.write( "8C5 * 7C1 =56*7=392 [5 odd, 1 even]
\n" ); document.write( "8C4 * 7C2 =70*21=1470 [4 odd, 2 even]
\n" ); document.write( "8C3 * 7C3 =56*35=1960 [3 odd, 3 even]
\n" ); document.write( "8C2 * 7C4 =28*35=980 [2 odd, 4 even]
\n" ); document.write( "8C1 * 7C5 =8*21=168 [1 odd, 5 even]
\n" ); document.write( "7C6=7 [all even]
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\n" ); document.write( "Adding all these numbers we get 5005 possible combinations.
\n" ); document.write( "Only those with an odd number of odd numbers give an odd result.
\n" ); document.write( "They are: 392+1960+168=2520
\n" ); document.write( "2520/5005=72/143 or .503497 Probability that the sum of the numbers will be odd.
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