document.write( "Question 770920: A and B ca do a job together in 7 days. A is 3/14 times as efficient as B. The same job can be done by A alone in ________. \n" ); document.write( "

Algebra.Com's Answer #469864 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+R%5Bb%5D+\"$ = B's rate of working in jobs / days
\n" ); document.write( " $\"+R%5Ba%5D+=+%28+3%2F14+%29%2AR%5Bb%5D+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "Together, their rate is ( 1 job ) / ( 7 days )
\n" ); document.write( " $\"+R%5Ba%5D+%2B+R%5Bb%5D+=+1%2F7+\"$
\n" ); document.write( " $\"+%28+3%2F14+%29%2AR%5Bb%5D+%2B+R%5Bb%5D+=+1%2F7+\"$
\n" ); document.write( " $\"+R%5Bb%5D+%2A%28+3%2F14+%2B+1+%29+=+1%2F7+\"$
\n" ); document.write( " $\"+%28+17+%2F+14+%29%2AR%5Bb%5D+=+2%2F14+\"$
\n" ); document.write( " $\"+17R%5Bb%5D+=+2+\"$
\n" ); document.write( " $\"+R%5Bb%5D+=+2%2F17+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+R%5Ba%5D+=+%28+3%2F14+%29%2AR%5Bb%5D+\"$
\n" ); document.write( " $\"+R%5Ba%5D+=+%28+3%2F14+%29%2A%28+2%2F17+%29+\"$
\n" ); document.write( " $\"+R%5Ba%5D+=+3%2F119+\"$
\n" ); document.write( " $\"+R%5Ba%5D+=+1%2F39.67+\"$
\n" ); document.write( "39 and 2/3 days
\n" ); document.write( "---------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+R%5Ba%5D+%2B+R%5Bb%5D+=+1%2F7+\"$
\n" ); document.write( " $\"+3%2F119+%2B+14%2F119+=+17%2F119+\"$
\n" ); document.write( " $\"+17+=+17+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );