document.write( "Question 1153346: A school dance committee is made up of 3 freshmen, 6 sophomores, 3 juniors, and 2 seniors.\r
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document.write( "How many ways are there to sit the committee in a row at a meeting if the students must sit together by grade?\r
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document.write( "How many ways are there to sit the committee in a row at a meeting if the freshman, sophomores, and juniors must sit by grade, but the seniors can sit wherever they want? \n" );
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Algebra.Com's Answer #775578 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Problem 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question: \n" ); document.write( "A school dance committee is made up of 3 freshmen, 6 sophomores, 3 juniors, and 2 seniors. \n" ); document.write( "How many ways are there to sit the committee in a row at a meeting if the students must sit together by grade?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: 1,244,160 (a little over 1 million)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------------- \n" ); document.write( "Work Shown:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The students must sit together by grade, so we effectively have 4 sections or blocks. There are 4! = 4*3*2*1 = 24 ways to arrange 4 blocks. Let A = 24.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Within the freshman block, there are 3! = 3*2*1 = 6 ways to arrange these students. Let B = 6. \n" ); document.write( "Within the sophomores block, there are 6! = 6*5*4*3*2*1 = 720 ways to arrange these students. Let C = 720. \n" ); document.write( "Within the juniors block, there are 3! = 3*2*1 = 6 ways to arrange these students. Let D = 6. \n" ); document.write( "Within the seniors block, there are 2! = 2*1 = 2 ways to arrange these students. Let E = 2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Put together, there are A*B*C*D*E = 24*6*720*6*2 = 1,244,160 different permutations possible such that the students must sit together by grade.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "============================================================== \n" ); document.write( "Problem 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question: \n" ); document.write( "A school dance committee is made up of 3 freshmen, 6 sophomores, 3 juniors, and 2 seniors. \n" ); document.write( "How many ways are there to sit the committee in a row at a meeting if the freshman, sophomores, and juniors must sit by grade, but the seniors can sit wherever they want?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: 3,110,400 (slightly over 3 million)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------------------------- \n" ); document.write( "Work Shown:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 3 blocks: freshmen, sophomores, juniors \n" ); document.write( "Then there are 2 seniors who can sit wherever they want. \n" ); document.write( "Effectively, there are 5 \"people\" (3 of which are groups of people)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A = 5! = 5*4*3*2*1 = 120 ways to arrange the five \"people\" \n" ); document.write( "B = 3! = 3*2*1 = 6 ways to arrange the freshmen within any particular block \n" ); document.write( "C = 6! = 6*5*4*3*2*1 = 720 ways to arrange the sophomores within any particular block \n" ); document.write( "D = 3! = 3*2*1 = 6 ways to arrange the juniors within any particular block \n" ); document.write( "A*B*C*D = 120*6*720*6 = 3,110,400 is the total number of permutations in which the freshmen, sophomores, and juniors must sit together but the seniors can sit anywhere they want. \n" ); document.write( " \n" ); document.write( " |