document.write( "Question 758269: a box contain a four red, three black, and five white marble. two marbles are randomly drawn from this box and the color of these marbles is observed.\r
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document.write( "1) write all the possible observations.
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document.write( "2)calculate the probability of selecting two marbles of same color. \n" );
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Algebra.Com's Answer #461359 by Theo(13342)![]() ![]() You can put this solution on YOUR website! see the following picture and the comments below: \n" ); document.write( " ![]() \n" ); document.write( "you have 66 possible combinations of drawing 2 balls at a time taken from 12 balls.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this is calculated by the combination formula of 12C2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "12C2 = (12*11) / (2*1) = 6*11 = 66\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the number of ways you can draw 2 red balls out of 4 = 4C2 \n" ); document.write( "the number of ways you can draw 2 black balls out of 3 = 3C2 \n" ); document.write( "the number of ways you can draw 2 white balls out of 5 = 5C2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4C2 equals (4*3) / (2*1) = 6 \n" ); document.write( "3C2 equals (3*2) / (2*1) = 3 \n" ); document.write( "5C2 equals (5*4) / (2*1 = 10\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "total ways you can get balls of the same color (either all red or all black or all white) equals 6 + 3 + 10 which equals 19.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the probability of getting all balls of the same color is therefore equal to 19 / 66.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |