document.write( "Question 1149556: if barbara were to paint her room alone, it would take 4 hours. her sister Sarah could do the job in 5 hours. How long would it take them working together? \n" ); document.write( "

Algebra.Com's Answer #770891 by ikleyn(52778) $\"\"$ $\"About$

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document.write( "Barbara makes    of the job per hour.\r\n" );
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document.write( "Sarah   makes    of the job per hour.\r\n" );
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document.write( "Workin together, the sisters make   +  =  +  =  of the job per hour.\r\n" );
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document.write( "It means, that the can complete the job in   =  hours, working together.\r\n" );
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\n" ); document.write( "\n" ); document.write( "This method requires making manipulations with fractions, only.
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\n" ); document.write( "\n" ); document.write( "If you want or if you need to solve it using equation/equations, do it as follows.\r
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document.write( "Let \"t\" be the time for two to complete the job, in hours.\r\n" );
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document.write( "Barbara makes    of the job per hour --- hence, she will make    of the job in \"t\" hours.\r\n" );
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document.write( "Sarah makes    of the job per hour --- hence, she will make    of the job in \"t\" hours.\r\n" );
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document.write( "Since they completes the entire work in t hours,\r\n" );
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document.write( "     +  = 1.\r\n" );
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document.write( "Multiply both sides by 4*5. You will get\r\n" );
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document.write( "    5t + 4t = 20,\r\n" );
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document.write( "    9t      = 20\r\n" );
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document.write( "     t      =   hours,   the same ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "Now you know two basic ways to solve this problem.\r
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\n" ); document.write( "\n" ); document.write( "It is a standard and typical joint work problem.\r
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\n" ); document.write( "\n" ); document.write( "There is a wide variety of similar solved joint-work problems with detailed explanations in this site. See the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Using Fractions to solve word problems on joint work \r
\n" ); document.write( "\n" ); document.write( "    - Solving more complicated word problems on joint work \r
\n" ); document.write( "\n" ); document.write( "    - Selected joint-work word problems from the archive \r
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\n" ); document.write( "\n" ); document.write( "Read them and get be trained in solving joint-work problems.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the topic
\n" ); document.write( "\"Rate of work and joint work problems\" of the section \"Word problems\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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