document.write( "Question 906025: It takes Ralph 14 hours to paint a fence alone. Lisa can do the same job in 18 hours. If Ralph paints alone for 45 minutes before Lisa begins helping, how long must they work together to finish painting the fence? Give your answer as a simplified fraction. \n" ); document.write( "
Algebra.Com's Answer #549602 by lwsshak3(11628)\"\" \"About 
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It takes Ralph 14 hours to paint a fence alone. Lisa can do the same job in 18 hours. If Ralph paints alone for 45 minutes before Lisa begins helping, \r
\n" ); document.write( "\n" ); document.write( " Give your answer as a simplified fraction.
\n" ); document.write( "***
\n" ); document.write( "1/14=Ralph's work rate
\n" ); document.write( "1/18=Lisa's work rate
\n" ); document.write( "1/14+1/18=18/252+14/252=32/252=8/63=work rate working together
\n" ); document.write( "let x=time working together to finish the job
\n" ); document.write( "45 min=3/4 hr
\n" ); document.write( "..
\n" ); document.write( "(3/4)(1/14)+x(8/63)=1 (100% of job)
\n" ); document.write( "3/56+8x/63=1
\n" ); document.write( "cd:56*63=3528
\n" ); document.write( "189+448x=3528
\n" ); document.write( "448x=3339
\n" ); document.write( "=3339/448≈7.45
\n" ); document.write( "how long must they work together to finish painting the fence?≈7.45 hrs \n" ); document.write( "
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