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A gardener completes maintenance in 12 hours. Another gardener takes 10 hours. How long will it take both gardeners?
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The rate of the 1-st gardener is job per hour.
It means that he does of his job in hour. In each hour.
The rate of the 2-nd gardener is job per hour.
It means that he does of his job in hour. In each hour.
When they work together, their rates are added.
Together they do of the entire work per hour.
= = of the job per hour.
Hence, they will complete the job in = hours = hours.
The lesson to learn from this solution:
There is no need to solve equations.
You can solve it using simple logic.
You also are supposed to operate freely with fractions. That's all.
Simple logic and fractions.
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For a wide variety of similar solved joint-work problems with detailed explanations 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
in this site.
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".