document.write( "Question 667143: One group of workers can do a job in 8 days. After this group has worked 3 days, another group joins it and together they complete the job in 3 more days. In what time could the second group have done the job alone? \n" ); document.write( "

Algebra.Com's Answer #414818 by josmiceli(19441) $\"\"$ $\"About$

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If the 1st group can do 1 job in 8 days,
\n" ); document.write( "they do 1/8 of the job in 1 day
\n" ); document.write( "So, in 3 days they do 3/8 of the job
\n" ); document.write( "That means 5/8 of the job is left to be done
\n" ); document.write( "------------------
\n" ); document.write( "Let $\"+d+\"$ = the number of days the 2nd
\n" ); document.write( "group takes to do the job alone.
\n" ); document.write( "Add their rates of working to get the rate
\n" ); document.write( "at which they can do the 5/8 of a job working together
\n" ); document.write( " $\"+1%2F8+%2B+1%2Fd+=+%285%2F8%29%2F3+\"$
\n" ); document.write( " $\"+1%2F8+%2B+1%2Fd+=+5%2F24+\"$
\n" ); document.write( "Multiply both sides by $\"+24d+\"$
\n" ); document.write( " $\"+3d+%2B+24+=+5d+\"$
\n" ); document.write( " $\"+2d+=+24+\"$
\n" ); document.write( " $\"+d+=+12+\"$
\n" ); document.write( "The 2nd group could have done the job alone in 12 days\r
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