document.write( "Question 916524: Julia and Robert can finish a piece of work in 15 days. Julia can do the job alone in 20 days. How long would it take Robert to do the task alone? \n" ); document.write( "

Algebra.Com's Answer #556141 by richwmiller(17219) $\"\"$ $\"About$

You can put this solution on YOUR website!
rate for A alone 20
\n" ); document.write( "rate for A & B together 15
\n" ); document.write( "1/a+1/b=1/x
\n" ); document.write( "1/20+1/b=1/15
\n" ); document.write( "1/b=1/15-1/20
\n" ); document.write( "1/b=20/300-15/300
\n" ); document.write( "1/b=5/300
\n" ); document.write( "1/b=1/60
\n" ); document.write( "b=60
\n" ); document.write( "rate for B alone 60
\n" ); document.write( "check
\n" ); document.write( "1/20+1/60=1/15
\n" ); document.write( "60/1200+20/1200=1/15
\n" ); document.write( "80/1200=1/15
\n" ); document.write( "ok
\n" ); document.write( "codewa\r
\n" ); document.write( "\n" ); document.write( "ewatrrr original mistake was\r
\n" ); document.write( "\n" ); document.write( "3x + 60 = 5x
\n" ); document.write( "which should have been
\n" ); document.write( "3x + 60 = 4x
\n" ); document.write( "then the next step is 60=x\r
\n" ); document.write( "\n" ); document.write( "ewatrrr own check is wrong\r
\n" ); document.write( "\n" ); document.write( "Her check should be
\n" ); document.write( " $\"3%2F60+%2B+2%2F60+=+5%2F60\"$
\n" ); document.write( " $\"3%2F60+%2B+2%2F60+=+1%2F12\"$
\n" ); document.write( "not
\n" ); document.write( " $\"3%2F60+%2B+2%2F60+=+1%2F15\"$ \r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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