SOLUTION: Martha can rake the leaves in her yard in two hours. Her brother can rake the leaves in six hours. How long will it take if they work together?

Question 1109813: Martha can rake the leaves in her yard in two hours. Her brother can rake the leaves in six hours. How long will it take if they work together?
Answer by ikleyn(52894) (Show Source): You can put this solution on YOUR website!
.

Martha does    of the job per hour.  It is her rate of work.


Brother does    of the job per hour.  It is his rate of work.


Working together,  they do   +  of the work per hour.


 +  =  +  =  = .


So, working together they make  of the job per hour.


It means that it will take   hours for them to complete the job working together.


 =  hours = 1 hour and 30 minutes.


Answer.  It will take   hours = 1 hour and 30 minutes for them to complete the job working together.

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It is a typical joint work problem.

There is a wide variety of similar solved joint-work problems with detailed explanations in this site. See the lessons
    - Using Fractions to solve word problems on joint work
    - Solving more complicated word problems on joint work
    - Selected joint-work word problems from the archive

Read them and get be trained in solving joint-work problems.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic
"Rate of work and joint work problems" of the section "Word problems".

Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.

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