The pH scale runs from 0 to 14 according to the book page 570 (Chapter 11 Section 7.A)

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The answer to this is B. In order to solve this, you need to divide the gallons with the square feet which means that 2,800,000 that you will divide with 500. The answer that you will get is 5600 gallons per square foot. There is a need for people to have filtered water especially at this day and age when the products that are available cannot entirely be considered clean.

There are a lot of health conditions that may arise from drinking unfiltered water. Some suffer from diarrhea but turn out fine after. Some people suffer from other more serious conditions that may cause them to become dehydrated. It is important that there is enough filter for the amount of water that needs to be cleaned.

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True. Many countries still have source of suitable drinking water without treatment.

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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%.

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The question does not suggest that the shape is irregular and so to calculate the answer in cubic feet, you merely have to multiply the length by the width by the height of the basin. It is easiest to multiply the first two, find the result and then multiply that by the third measure.

In the case of this rectangular basin the correct option is D. The earlier options may be the result of faulty multiplication attempts. The answer is 5,800 cubic feet.

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The correct answer to this item is letter D. To get the surface area of a circle, one must use the formula r squared multiply by pi. Since the radius is not given, divide the diameter by 2. So, 55 ft divided by 2 is 27.5 and this will be the radius.

Next, multiply 27.5 by 27.5 and the product will be 756.25. The value of pi is 3.14 where we multiply 756.25 to it. We will get the answer of 2,374.625. Usually, the answer is rounded off to retain a whole number; the final answer will be 2,375 square feet. Whether the radius or the diameter is given and memorize the value of pi, you can easily solve for the surface area of circles.

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I agree that proof of professional competence is essential ('C')l, but I think that 'D' should be added as well since there is no better way to demonstrate knowledge of essential rules and regulations than with a comprehensive examination. Thank You, Carlos Velez.

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92mL/min, 92.0297

There are two difficult aspects to this problem, specific gravity, and the percentage of alum in the solution.

*Math Constant: *Specific gravity of water = 1

*Math Constant:* 1 gram of water = 1mL

*Math Constant:* There are 1000 grams of water in one liter, and one milligram is one thousandth of a gram, so one milligram per liter (mg/L) is one millionth of a liter

*Math Constant:* 1,440 minutes in one day

*Math Constant:* 1 gallon = 3.785 liters

**Step 1:** 2.5mgd x 3.785 = 9.4625 million liters, 1 milligram is one millionth of a liter so 9.4625 liters is 1mg/L of 9.4625 million liters

**Step 2**: We need 9mg/L so, 9.4625 x 9 = 85.1625 liters of solution

**Step 3:** The liquid alum contains only 485 milligrams per milliliter. This is like saying it contains 485 parts alum out of 1000, or that it contains 48.5% alum. Because our solution is less than 100% we need to divide our needed amount by the percentage of the solution. So, 85.1625 / 48.5% = 175.59278 liters of a 48.5% solution needed.

**Step 4:** The liquid alum has a higher specific gravity (heavier per gallon) than water so we need less of it. 175.59278 / 1.325 = 132.52285 liters of liquid alum per day needed

**Step 5:** 1,440 minutes in one day so 132.52285 / 1440 = 0.0920297 liters per minute needed

**Step 6:** 1,000 milliliters in 1 liter, so 0.0920297 x 1000 = 92.0297 mL/min

*I hope that helped :)*

There are two difficult aspects to this problem, specific gravity, and the percentage of alum in the solution.

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mg/l and ppm are the same

1.6 million gallons x 8.34lbs per gallon = 13.344 million pounds, so 13.344 is 1ppm of 1.6 million gallons

28lbs / 13.344 =2.0983213 rounded to 2.1

1 Answer

A. The curve of the surface of a liquid

C. The proper line of vision to read a liquid in a buret

C. The proper line of vision to read a liquid in a buret

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