Answer: One 8-cm pipe (Its is greater than the total area of of two 4-cm pipes)
Explanation:
The area of a circle can be calculate with this formula:
![A=\pi r^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j29wdsg40jbed167khn7fs44y2z9velxu7.png)
Where "r" is the radius of the circle.
We need to calculate the area of 8-cm pipe. In this case:
![r=8cm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/k8jcl03op06lubg5c7gdzjm1rjqsdemuf1.png)
Then, substituting the radius into the formula, we get:
![A=\pi (8cm)^2\\\\A=201.06cm^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/49r6uvk5yl1u5gp2l63tm8exphq90xwn7x.png)
Now we must calculate the area of the two 4-cm pipes.
Since they are two pipes, the formula is:
In this case:
Then, substituting into the formula, we get:
![A=2\pi (4cm)^2\\\\A=100.53cm^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gmye2ubyre6h9b79lbodmcp0bj1v4ejn1u.png)
Therefore, since the area of one 8-cm pipe is greater than the total area of of two 4-cm pipes, we conclude that the pipe configuration that can deliver more water to residents is:
One 8-cm pipe