document.write( "Question 718810: a new photocopier works 4 times as fast as an old one. when the machines work together, a unicersity can produce all its staff manuals in 12 hr. find the time it would take each machine working alone to complete the job \n" ); document.write( "

Algebra.Com's Answer #441071 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+R+\"$ = the rate of old copier in ( copy job ) / ( hrs )
\n" ); document.write( "Let $\"+4R+\"$ = the rate of the new copier
\n" ); document.write( "Add the rates to get the rate working together
\n" ); document.write( " $\"+R+%2B+4R+=+1%2F12+\"$ ( 1/12 means ( 1 copy job ) / ( 12 hrs ) )
\n" ); document.write( " $\"+5R+=+1%2F12+\"$
\n" ); document.write( " $\"+R+=+1%2F60+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+4R+=+4%2F60+\"$
\n" ); document.write( " $\"+4R+=+1%2F15+\"$
\n" ); document.write( "-------------
\n" ); document.write( "The old copier can complete the job in 60 hrs working alone
\n" ); document.write( "The new copier can complete the job in 15 hrs working alone
\n" ); document.write( " \n" ); document.write( "

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