document.write( "Question 1013760: Max can finish repairing a machine in 4 hours. His helper can do the same job in 8 hours. Max began the job alone and work for 2 hours.His helper joined until the job was completed. How long did it take them to finish the job? \n" ); document.write( "

Algebra.Com's Answer #630046 by josmiceli(19441) $\"\"$ $\"About$

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What fraction of the job did Max
\n" ); document.write( "get done in 2 hrs?
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\n" ); document.write( "Max's rate of working:
\n" ); document.write( "[ 1 machine repaired ] / [ 4 hrs ] = $\"+1%2F4+\"$
\n" ); document.write( "Fraction of job done in 2 hrs:
\n" ); document.write( " $\"+%28+1%2F4+%29%2A2+=+1%2F2+\"$
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\n" ); document.write( "There is $\"+1+-+1%2F2+=+1%2F2+\"$ of the job left to do
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\n" ); document.write( "Let $\"+t+\"$ = time in hrs for them to finish job working together
\n" ); document.write( "Add their rates of working to get their rate working together
\n" ); document.write( " $\"+1%2F4+%2B+1%2F8+=+%28%28+1%2F2%29%29+%2F+t+\"$
\n" ); document.write( "Multiply both sides by $\"+8t+\"$
\n" ); document.write( " $\"+2t+%2B+t+=+4+\"$
\n" ); document.write( " $\"+3t+=+4+\"$
\n" ); document.write( " $\"+t+=+4%2F3+\"$ hrs
\n" ); document.write( "It took them 4/3 hrs = 1 hr and 20 min to finish
\n" ); document.write( "the job working together \n" ); document.write( "

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