document.write( "Question 502811: Jonathan can type a 20 page document in 40 minutes, Susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document? \n" ); document.write( "
Algebra.Com's Answer #338955 by Edwin McCravy(20056)\"\" \"About 
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Jonathan can type a 20 page document in 40 minutes, Susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document?
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document.write( "Let the answer be x minutes for all three working together\r\n" );
document.write( "to type 1 document.\r\n" );
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document.write( "Make this chart:\r\n" );
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document.write( "                   number         time            rate \r\n" );
document.write( "                 of documents      in              in\r\n" );
document.write( "                    typed        minutes     documents/minute\r\n" );
document.write( "Jonathan alone\r\n" );
document.write( "Susan alone\r\n" );
document.write( "Jack alone\r\n" );
document.write( "All working together\r\n" );
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document.write( "Fill in x for the time for all three working together.  Put 1 for \r\n" );
document.write( "the number of documents typed in all four cases.  Fill in the times \r\n" );
document.write( "that are given for each person working alone:\r\n" );
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document.write( "                   number         time            rate \r\n" );
document.write( "                 of documents      in              in\r\n" );
document.write( "                    typed        minutes     documents/minute\r\n" );
document.write( "Jonathan alone        1            40 \r\n" );
document.write( "Susan alone           1            30\r\n" );
document.write( "Jack alone            1            24 \r\n" );
document.write( "All working together  1             x\r\n" );
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document.write( "Next fill in the rates in documents/minute by dividing the\r\n" );
document.write( "number of documents typed by the time:\r\n" );
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document.write( "                   number         time            rate \r\n" );
document.write( "                 of documents      in              in\r\n" );
document.write( "                    typed        minutes     documents/minute\r\n" );
document.write( "Jonathan alone        1            40              1/40 \r\n" );
document.write( "Susan alone           1            30              1/30  \r\n" );
document.write( "Jack alone            1            24              1/24\r\n" );
document.write( "All working together  1             x              1/x \r\n" );
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document.write( "Use the equation:\r\n" );
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document.write( "\"1%2F40%2B1%2F30%2B1%2F24=1%2Fx\"\r\n" );
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document.write( "Solve that and get x=10 minutes\r\n" );
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document.write( "Edwin
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