document.write( "Question 203045: Three people, each working at the same rate, finish a job in 20 hours. At this rate, how many hours will it take five people to finish three such jobs? \n" ); document.write( "

Algebra.Com's Answer #153196 by ptaylor(2198) $\"\"$ $\"About$

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\n" ); document.write( "Let x=amount of time it takes five people to finish one job, then
\n" ); document.write( "3x=amount of time it takes five people to finish 3 such jobs
\n" ); document.write( "ok. Three people work at the rate of 1/20 of the job per hour, so one person works at the rate of (1/20)/3 or 1/60 of the job per hour\r
\n" ); document.write( "\n" ); document.write( "Five people work at the rate of 5*(1/60) or 5/60 of the job per hour
\n" ); document.write( "So, our equation to solve is:
\n" ); document.write( "(5/60)*x=1 (1 job, that is)
\n" ); document.write( "5x=60
\n" ); document.write( "x=12 hours--------------amount of time it takes five people to complete 1 job
\n" ); document.write( "3x=3*12=36 hours ------------amount of time it takes five people to complete three such jobs\r
\n" ); document.write( "\n" ); document.write( "Another way to look at this problem:\r
\n" ); document.write( "\n" ); document.write( "If three persons can complete the job in 20 hours, then the job requires 3*20 or 60 person-hours to complete. Three such jobs would require 3*60 or 180 person-hours to complete\r
\n" ); document.write( "\n" ); document.write( "So, five persons could complete three such jobs in 180/5=36 hours \r
\n" ); document.write( "\n" ); document.write( "Hope this helps----ptaylor \n" ); document.write( "

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