What is the percent of water filtered that is used for backwashing if - ProProfs Discuss

# What is the percent of water filtered that is used for backwashing if a plant filters 1.8 million gallons and 28,000 gallons of filtered water is used for backwashing?

A. 1.11%
B. 1.22%
C. 1.30%
D. 1.39%
E. 1.56%

This question is part of CA Water Treatment Plant Operator Quiz Chapter 6
Asked by PaulMJr, Last updated: Feb 24, 2020

#### E. Austin

E. Austin

The correct answer to this question is E, 1.56%. To get this answer, we can divide the given values in the word problem. We will divide the 28 thousand gallons of filter water by the 1.8 million values of backwashing. This will provide us with 0.0155555556. This would be the correct answer, except the question is asking for a percent.

To get the percent, we would need to move the decimal point in the value two spaces to the right. This gives us 1.55. We don't see 1.55% as one of the multiple choice answers, so we would round up the second 5 to 6, being that the following numbers are more significant. This will give us an answer of 1.56%.

#### RagweedFarmer

RagweedFarmer

1.55555%

28,000/1,800,000=0.0155555, move decimal point to places to the right to get percent

John Smith