SOLUTION: John can cut the grass in 4 hours working by himself. When John cuts the grass with his younger brother Dino, it takes 3 hours. How long would it take for Dino to cut the grass if

Question 1087709: John can cut the grass in 4 hours working by himself. When John cuts the grass with his younger brother Dino, it takes 3 hours. How long would it take for Dino to cut the grass if he worked by himself?
Answer by ikleyn(52858) (Show Source): You can put this solution on YOUR website!
.

Their combined rate of work is  of the job per hour.

John's individual rate of work is  of the job per hour.

Hence, Dino's individual rate of work is  =  =  of the job per hour.

It means that Dino can make all the job in 12 hours working alone.

Solved.

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".

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