document.write( "Question 816422: new copy machine takes 20 mins to copy exams
\n" ); document.write( "old copy machine take 30 mins to copy exams
\n" ); document.write( "how long does it take if both copy machines are used?
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Algebra.Com's Answer #492536 by richwmiller(17219)\"\" \"About 
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x/20+x/30=1
\n" ); document.write( "3x/60+2x/60=1
\n" ); document.write( "5x/60=1
\n" ); document.write( "x/12=1
\n" ); document.write( "x=12 mins
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