document.write( "Question 473509: Dear math teacher, \r
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document.write( "I am having difficulites solving the following math problem: \r
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document.write( "In how many ways can 9 different prizes be awarded to two students so that one receives 3 and the other 6? \r
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document.write( "So far, I got two answers but they are incorrect. The correct answer is 168. \r
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document.write( "Here is what I did so far:
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document.write( "First, I said to myself, this might be done this way: Permutation = 9 factorial divided by (3 factorial times 6 factorial) and that equals to 84. However, that's not the right answer. So then, I calculated: Permutation of 9 things taken 3 at a time TIMES Permution of 6 things taken 6 at time = 82.080. However, it's not the right answer either. \r
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document.write( "Would you please help me solve this problem? Thank you so much. \r
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document.write( "Yours, \r
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document.write( "I. \n" );
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Algebra.Com's Answer #324726 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! Let's say there are 2 students A and B\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's focus on how many ways to assign 3 prizes to student A.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 9*8*7 = 504 different ways to assign 3 prizes (out of 9) to student A where order matters. Since order does NOT matter, we divide by 3! = 6 to get 504/6 = 84. Note: this is to ignore combinations that have been counted more than once.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So there are 84 ways to assign 3 prizes to student A where order does NOT matter.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now do the same work for student B to get 84 different ways as well. Basically repeat the above, but replace \"Student A\" with \"Student B\".\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So there are 84+84=168 different ways to assign 3 prizes to one student and 6 prizes to the other. \n" ); document.write( " |