If the previous reading of a water meter was 1932 and the current reading is 9159, how much water has been used?

To determine how much water has been used, you need to subtract the previous reading of the water meter from the current reading. In this case, the previous reading is 1932, and the current reading is 9159.

Performing the calculation:

9159 (current reading) - 1932 (previous reading) = 7227 cubic meters.

This calculation shows that the total amount of water used is 7227 cubic meters, making this the correct answer. Understanding this process is essential, as it demonstrates the method for calculating water usage based on meter readings, which is a fundamental task for sewage treatment workers involved in monitoring and managing water resources.