`1/x+4/x=1/72`
In order to create safe drinking water, cities and towns use water treatment facilities to remove contaminants from surface water and groundwater. Suppose a town has a treatment plant but decides to build a second, more efficient facility. The new treatment plant can filter the water in the reservoir four times as quickly. Working together, the two facilities can filter all the water in the reservoir in 72 hours. The equation above represents the scenario. Which of the following describes what the term `(1)/(x)` represents.

Options

A. The portion of the water the older treatment plant can filter in 1 hour
B. The time it takes the order treatment plant to filter the water in the reservoir
C. The time it takes the order treatment plant to filter `(1)/(72)` of the water in the reservoir
D. The portion of the water the new treatment plant can filter in 4 hour

Answer

A