document.write( "Question 745788: Peter and Paul can do a certaion job in 3 hours. On a given day, they worked together for 1 hour then Paul left and Peter finishes the rest of the work in 8 more hours. How long will it take Peter to do the job alone? \n" ); document.write( "

Algebra.Com's Answer #454019 by josmiceli(19441) $\"\"$ $\"About$

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If they can do the whole job in 3 hrs working
\n" ); document.write( "together, then in 1 hour, they can do $\"+1%2F3+\"$
\n" ); document.write( "of the job
\n" ); document.write( "That means there is 2/3 of the job left to do
\n" ); document.write( "-----------------
\n" ); document.write( "Then, ( Peter's rate of working ) x ( 8 hrs ) = 2/3
\n" ); document.write( "Let $\"+R%5B1%5D+\"$ = Peter's rate of working
\n" ); document.write( " $\"+8R%5B1%5D+=+2%2F3+\"$
\n" ); document.write( " $\"+R%5B1%5D+=+2%2F24+\"$
\n" ); document.write( " $\"+R%5B1%5D+=+1%2F12+\"$
\n" ); document.write( "Peter would take 12 hrs to do the job alone
\n" ); document.write( "check:
\n" ); document.write( "----------
\n" ); document.write( "Let $\"+R%5B2%5D+\"$ = Paul's rate of working
\n" ); document.write( " $\"+R%5B1%5D+%2B+R%5B2%5D+=+1%2F3+\"$
\n" ); document.write( " $\"+1%2F12+%2B+R%5B2%5D+=+1%2F3+\"$
\n" ); document.write( " $\"+R%5B2%5D+=+4%2F12+-+1%2F12+\"$
\n" ); document.write( " $\"+R%5B2%5D+=+1%2F4+\"$
\n" ); document.write( "In $\"+1+\"$ hr,
\n" ); document.write( " $\"+1%2F12+%2B+3%2F12+=+x%2F1+\"$
\n" ); document.write( " $\"+x+=+1%2F3+\"$
\n" ); document.write( "So, $\"+2%2F3+\"$ of the job is left
\n" ); document.write( "Peter does
\n" ); document.write( " $\"+1%2F12++=+%282%2F3%29+%2F+8+\"$
\n" ); document.write( " $\"+1%2F12+=+1%2F12+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "
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