document.write( "Question 48480: Signals are sent from a battleship by placing four flags on a vertical pole. How many different signals can be formed by selecting the four flags from\r
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document.write( "1. Four different colored flags\r
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document.write( "2. Two different red flags & two identical white flags \n" );
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Algebra.Com's Answer #32079 by longjonsilver(2297)![]() ![]() You can put this solution on YOUR website! 1 4 different red flags:\r \n" ); document.write( "\n" ); document.write( "first flag: 4 possibles \n" ); document.write( "second flag: 3 possibles (since one has been chosen as the first flag) \n" ); document.write( "third flag: 2 possibilities \n" ); document.write( "fourth flag: 1 possible flag.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Total: 4*3*2*1 --> 24 possible ways\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2. 2 different red flags (r and R) and 2 identical white flags (W and W)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Permutations are, in order: \n" ); document.write( "rRWW \n" ); document.write( "rWRW \n" ); document.write( "rWWR\r \n" ); document.write( "\n" ); document.write( "RrWW \n" ); document.write( "RWrW \n" ); document.write( "RWWr\r \n" ); document.write( "\n" ); document.write( "WWrR \n" ); document.write( "WWRr \n" ); document.write( "WrRW \n" ); document.write( "WRrW \n" ); document.write( "WrWR \n" ); document.write( "WRWr\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "so answer is 12. Now algebraically we get this by starting with the 24 as the answer for 4 different flags and then dividing by 2! since we have 2 identical flags (the white ones):\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "24/2! \n" ); document.write( "24/2 \n" ); document.write( "12\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Hope this is clear.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "jon. \n" ); document.write( " \n" ); document.write( " |