Answer:
About 6 hours.
Explanation:
The cylinder has a diameter of 10 meters and a depth of 1.4 meters.
First, we can find the volume of the cylinder, given by the formula:
![V=\pi r^2h](https://img.qammunity.org/2022/formulas/mathematics/high-school/epjh35sj5an0p978o7hjzs2ufmx9ct9m3d.png)
Where r is the radius and h is the height (or depth, in this case).
Since our diameter is 10, our radius is 5.
Therefore, the volume of the cylinder will be (using 3.14 as π):
![V=(3.14)(5)^2(1.4)=109.9\text{ meters} ^3](https://img.qammunity.org/2022/formulas/mathematics/high-school/mhvsysk4c725uvxktmwoivi499fpywoz3l.png)
Since water is pumped at a rate of 18 cubic meters per hour, it will take then:
![109.9/18=6.10\overline{5}\approx 6\text{ hours}](https://img.qammunity.org/2022/formulas/mathematics/high-school/gjfnjqjbkk6vo8bgaz95ohbu8drlzqbbc9.png)
So, it will take about 6 hours for the water to completely fill the pool.