# Exam Study Guide: Problem Solving

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When operators are faced with licensing exams, they sometimes struggle with test anxiety because they don’t fully understand how to properly study and prepare for exam questions. Here we take a look at a sample wastewater treatment licensing exam question, how to solve the problem, and the correct answer.

Sample Question:

All licensed operators have been tested on math skills that apply to the discipline for which they are certified. With wastewater, they need to know a long list of mathematical functions and formulas that will be used frequently with day-to-day operations.

a. To troubleshoot the plant when needed
b. To aid with engineering
c. To balance the operations with influent and effluent flows
d. To control the bacteria development within the system

All wastewater treatment facilities operate the same way with regards to hydraulics (the flow of water through the process), however, with each process, solids are removed and water is lost through evaporation. The solids are not removed in dry form but are removed in wet form and thus the flow is reduced with each process through the system.

With each loss, each unit then has different detention times than the previous unit. In order to balance the influent with effluent, these losses need to be factored into the operations. So the influent flow will never balance with the effluent flow.

Therefore, the correct answer is c) To balance the operations with the influent and effluent flows.

Even though these numbers will never be identical, each unit will have a reduced flow entering so operators need to know what that flow is and how it will affect the expectations of the operation.