document.write( "Question 445982: If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it?
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Algebra.Com's Answer #307104 by Edwin McCravy(20055)\"\" \"About 
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If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it?
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document.write( "Make this chart\r\n" );
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document.write( "       no. of jobs done     time in days     rate in jobs/day\r\n" );
document.write( "Sam           \r\n" );
document.write( "Lisa          \r\n" );
document.write( "Tom         \r\n" );
document.write( "All 3         \r\n" );
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document.write( "Let x be the time it takes all of them to complete the job.\r\n" );
document.write( "Fill in the other given times:\r\n" );
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document.write( "       no. of jobs done     time in days     rate in jobs/day\r\n" );
document.write( "Sam                              4                  \r\n" );
document.write( "Lisa                             6                   \r\n" );
document.write( "Tom                              2                   \r\n" );
document.write( "All 3                            x                   \r\n" );
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document.write( "In all four cases exactly 1 job was done, so we fill in the\r\n" );
document.write( "number of jobs in every case as 1:\r\n" );
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document.write( "       no. of jobs done     time in days     rate in jobs/day\r\n" );
document.write( "Sam           1                  4                  \r\n" );
document.write( "Lisa          1                  6                   \r\n" );
document.write( "Tom           1                  2                   \r\n" );
document.write( "All 3         1                  x                   \r\n" );
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document.write( "Now we fill in the rates in jobs/day by dividing the number of\r\n" );
document.write( "jobs by the number of days required to complete it:\r\n" );
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document.write( "       no. of jobs done     time in days     rate in jobs/day\r\n" );
document.write( "Sam           1                  4                  1/4\r\n" );
document.write( "Lisa          1                  6                  1/6 \r\n" );
document.write( "Tom           1                  2                  1/2 \r\n" );
document.write( "All 3         1                  x                  1/x \r\n" );
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document.write( "Now that the chart is filled in, we use the fact that the sum\r\n" );
document.write( "of the individual rates equals to the rate of all 3 working\r\n" );
document.write( "together, so\r\n" );
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document.write( "                1/4 + 1/6 + 1/2 = 1/x\r\n" );
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document.write( "Solve that by multiplying through by the LCD of 12x\r\n" );
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document.write( "Answer:  12/11 = 1 1/11 days\r\n" );
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document.write( "Edwin
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