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Tom paints a fence in 4 hours.Huck paints the fence in 6 hours. How long does it take for them to paint the fence working together?
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Tom paints of the fence length in one hour (in each hour).
It is his rate of work.
Huck paints of the fence length in one hour (in each hour).
It is Huck's rate of work.
When the both work together, they paint = = of the fence length in one hour. In each hour.
So, their combined rate of work is the sum of the individual rates and is equal to of the fence length per hour.
It means that the both will complete their job in of an hour.
of an hour is 12 minutes. of the hour is 12*12 = 144 minutes, or 2 hours and 24 minutes.
Answer. Both boys will complete the job in 2 hours and 24 minutes.
On solving joint work problems see the lessons
- Rate of work problems,
- 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.