document.write( "Question 842435: Four men and eight women are to line up for a picture with the four men in the middle. How many ways can this be done? (Assume there are four women on each side of the group of men) \n" ); document.write( "
Algebra.Com's Answer #507582 by Theo(13342)![]() ![]() You can put this solution on YOUR website! the 4 men in the middle can be arranged 4! ways. \n" ); document.write( "the 8 women all in a row can be arranged in 8! ways. \n" ); document.write( "the total number of ways will be 4! * 8! = 967,680 ways \n" ); document.write( "you take the 8 women in a row and split them in half and stick the 4 men in the middle. \n" ); document.write( "4! is equal to 24 \n" ); document.write( "8! is equal to 40320. \n" ); document.write( "for each of the 40320 arrangements of the women, you can stick 24 arrangements of the men in the middle. \n" ); document.write( "this makes the total number of arrangements equal to 24 * 40320 which is equal to 967680.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let's assume smaller numbers so you can see what's happening. \n" ); document.write( "assume 2 men and 4 women. \n" ); document.write( "the men can be arranged in 2! ways which is equal to 2. \n" ); document.write( "the women can be arranged in 4! ways which is equal to 24. \n" ); document.write( "the total ways they can be arranged is 2 * 24 = 48. \n" ); document.write( "let letters represent the men and let number represent the women. \n" ); document.write( "the letters will be a and b. \n" ); document.write( "the numbers will be 1 and 2 and 3 and 4. \n" ); document.write( "the men can be arranged as: \n" ); document.write( "ab \n" ); document.write( "ba \n" ); document.write( "the women can be arranged as:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1234 \n" ); document.write( "1243 \n" ); document.write( "1324 \n" ); document.write( "1342 \n" ); document.write( "1423 \n" ); document.write( "1432 \n" ); document.write( "2134 \n" ); document.write( "2143 \n" ); document.write( "2314 \n" ); document.write( "2341 \n" ); document.write( "2413 \n" ); document.write( "2431 \n" ); document.write( "3124 \n" ); document.write( "3142 \n" ); document.write( "3214 \n" ); document.write( "3241 \n" ); document.write( "3412 \n" ); document.write( "3421 \n" ); document.write( "4123 \n" ); document.write( "4132 \n" ); document.write( "4213 \n" ); document.write( "4231 \n" ); document.write( "4312 \n" ); document.write( "4321\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "all you do now is split the 4 women down the middle and stick the 2 men in between. \n" ); document.write( "each of the 24 arrangements for the women will contain 2 arrangements for the men, so you will wind up with 2 * 24 = 48 total arrangements.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I'll show you what happens with the first arrangement of the women.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first arrangement is:\r \n" ); document.write( "\n" ); document.write( "1234\r \n" ); document.write( "\n" ); document.write( "the 2 arrangements for the men are ab and ba\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "stick the 2 men in the middle and you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "12 ab 34 \n" ); document.write( "12 ba 34\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this happens with all 24 arrangements of the women, so the total number of arrangements becomes 48.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |