document.write( "Question 1151727: A bag contains four red marbles, one green one, one lavender one, three yellows,
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document.write( "and two orange marbles.
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document.write( "How many sets of five marbles include at most one of the yellow ones? \n" );
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Algebra.Com's Answer #773608 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "If there is a way to distinguish between the marbles of the same color, say there's a numeric label on each marble, then the answer is 756 as Edwin has shown. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If there isn't a way to tell two red marbles apart, and similar for the other colors, then the answer is 23.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Below shows the work on how to get 23.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "==================================================================\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We have this multiset \n" ); document.write( "{R, R, R, R, G, L, Y, Y, Y, A, A} \n" ); document.write( "where \n" ); document.write( "R = red marble \n" ); document.write( "G = green marble \n" ); document.write( "L = lavender marble \n" ); document.write( "Y = yellow marble \n" ); document.write( "A = orange marble (I'm using the letter \"A\" instead of the letter \"O\" because it is easilly mixed up with the number zero)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can write this shorthand notation \n" ); document.write( "4R, 1G, 1L, 3Y, 2A \n" ); document.write( "to indicate 4 red, 1 green, 1 lavender, 3 yellow, 2 orange\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We want to select five marbles such that we only have at most 1 yellow marble. This means we either have 1 yellow or no yellows. So we can toss out 2 of the yellow marbles getting this updated notation \n" ); document.write( "4R, 1G, 1L, 1Y, 2A \n" ); document.write( "We are able to toss any two yellow marbles because we can't tell them apart.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now consider the number of ways we can add to 5 using positive integers. There are 6 ways to do this \n" ); document.write( "4+1 \n" ); document.write( "3+2 \n" ); document.write( "3+1+1 \n" ); document.write( "2+2+1 \n" ); document.write( "2+1+1+1 \n" ); document.write( "1+1+1+1+1 \n" ); document.write( "These are considered partitions and will help us figure out how to select the marbles in an organized way.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Partition 4+1 \n" ); document.write( "We have 4 red marbles. No other color has this many marbles. So the '4' applies to red only. The '1' applies to any of the other colors. We have 4 other colors, so we have 4 ways to fill out this partition \n" ); document.write( "4R,1G \n" ); document.write( "4R,1L \n" ); document.write( "4R,1Y \n" ); document.write( "4R,1A\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------- \n" ); document.write( "Partition 3+2 \n" ); document.write( "No color has 3 marbles other than red, so the '3' applies to the red marbles. No other color than orange has 2 marbles (recall we tossed out 2 yellows leaving with just 1), so the '2' applies to orange \n" ); document.write( "There is only one way we can have 3 marbles of one color and 2 marbles of another color \n" ); document.write( "3R, 2A\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------- \n" ); document.write( "Partition 3+1+1 \n" ); document.write( "The '3' applies to the red marbles. The other '1's are for the other colors \n" ); document.write( "3R,1Y,1A \n" ); document.write( "3R,1L,1A \n" ); document.write( "3R,1L,1Y \n" ); document.write( "3R,1G,1A \n" ); document.write( "3R,1G,1Y \n" ); document.write( "3R,1G,1L \n" ); document.write( "There are 6 ways to fill this section out.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------- \n" ); document.write( "Partition 2+2+1 \n" ); document.write( "The '2's apply to the red and orange marbles. The '1' is for the other colors \n" ); document.write( "2R,1Y,2A \n" ); document.write( "2R,1L,2A \n" ); document.write( "2R,1G,2A \n" ); document.write( "There are 3 ways to do it here.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------- \n" ); document.write( "Partition 2+1+1+1 \n" ); document.write( "The '2' either applies to red marbles or orange marbles. The '1's are for anything else \n" ); document.write( "2R,1L,1Y,1A \n" ); document.write( "2R,1G,1Y,1A \n" ); document.write( "2R,1G,1L,1A \n" ); document.write( "2R,1G,1L,1Y \n" ); document.write( "1G,1L,1Y,2A \n" ); document.write( "1R,1L,1Y,2A \n" ); document.write( "1R,1G,1Y,2A \n" ); document.write( "1R,1G,1L,2A \n" ); document.write( "There are 8 rows in the list above.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------------- \n" ); document.write( "Partition 1+1+1+1+1 \n" ); document.write( "There's only one way to do this selection and that is to simply pick one of each color \n" ); document.write( "1R,1G,1L,1Y,1A\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Add up the subtotals: \n" ); document.write( "4+1+6+3+8+1 = 23\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here are all 23 ways to select five marbles in which we cannot tell similar color ones apart (eg: we can't tell two red marbles apart) \n" ); document.write( "
\n" ); document.write( "The order of the selection does not matter. \n" ); document.write( "So 1R,1G,1L,1Y,1A is the same as 1G,1R,1L,1Y,1A\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |