SOLUTION: Bert can clean the sidewalks around the building in 2hours by using blower.Dennis can do the same job in 8 hours using a broom.how long it take them working together.

Question 1111625: Bert can clean the sidewalks around the building in 2hours by using blower.Dennis can do the same job in 8 hours using a broom.how long it take them working together.
Answer by ikleyn(52803) (Show Source): You can put this solution on YOUR website!
.

Bert   makes    of the job per hour.  It is his rate of work.


Dennis makes    of the job per hour.  It is his rate of work.


Working together, they make   +  of the job per hour.


    When they work together, their rates are summing up !


 +  =  +  = .


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


Hence, it will take them    hours = 8*12 minutes = 96 minutes = 1 hour and 36 minutes 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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