Monday, July 13, 2009

Introductory-Level Math Practice Test

1. A water treatment plant uses a ferric sulfate dosage of 50 mg/l on Monday, 42 mg/l on Tuesday, 60 mg/l on Wednesday, 56 mg/l on Thursday, and 52 mg/l on Friday. What was the plant's average ferric sulfate dosage for this five-day period?

A. 51 mg/l
B. 52 mg/l
C. 53 mg/l
D. 54 mg/l

2. How many pounds of sodium hydoxide will a water treatment plant use if the plant treats 25 million gallons of water with a dosage of 17 ppm?

A. 1459.5 lbs.
B. 4595.8 lbs.
C. 3544.5 lbs.
D. 1514.3 lbs

3. How many gallons of water will a standpipe hold if the standpipe has an inside diameter of ten feet and a fill-height of sixty feet?

A. 157,126 gallons
B. 118,840 gallons
C. 314,000 gallons
D. 35,231 gallons

4. How is the fraction 1/25 written in decimal form?

A. .025
B. .25
C. .04
D. .60

5. What is a water treatment plant's sodium hydroxide dosage if the plant uses 2000 pounds of sodium hydroxide to treat 12 MG of water?

A. 15 mg/l
B. 20 mg/l
C. 25 mg/l
D. 30 mg/l

6. How is 3,015,000 gallons written in million-gallon notation?

A. 3.015 MG
B. 3.150 MG
C. 3.0015 MG
D. None of the above

7. How much pressure will a 70-foot column of water exert at its base?

A. 70 psi
B. 231 psi
C. 50 psi
D. 30 psi

8. How many gallons of water can be held in an 80-foot length of 12" stainless steel piping?

A. 537.6 gallons
B. 314.2 gallons
C. 469.7 gallons
D. 246.3 gallons

9. How many gallons of water can be dosed with 3000 pounds of alum if the alum is applied at a dosage of 45 ppm?

A. 5 MG
B. 8 MG
C. 10 MG
D. 12 MG

10. How many pounds of lime will be required to dose 19,000,000 gallons of water with a lime dosage of 3.5 mg/l?

A. 555 pounds
B. 612 pounds
C. 437 pounds
D. 296 pounds

11. What is a water treatment plant's orthophosphate dosage if the plant uses 200 pounds of orthophosphate to treat 24 million gallons of water?

A. .75 mg/l
B. 1.5 mg/l
C. 2.0 mg/l
D. 1.0 mg/l

12. How is 32 percent written in decimal form?

A. 32.0
B. .032
C. .32
D. .302

13. How many pounds of alum will a water treatment plant use to dose 36,000,000 gallons of water with a dosage of 58 ppm?

A. 12,312 lbs.
B. 17,414 lbs.
C. 10,221 lbs.
D. 19,642 lbs.

14. What is the detention time in a basin if the basin holds 200,000 gallons of water, and the flow through the basin is 1.2 MGD?

A. 4 hours
B. 3 hours
C. 6 hours
D. None of the above

15. What is a water treatment plant's filtration rate if the plant has eight 12' x 16' mixed-media filters, and the flow through the plant is 6144 gpm?

A. 2 gpm/ft2
B. 3 gpm/ft2
C. 4 gpm/ft2
D. 5 gpm/ft2


ANSWERS: 1. B; 2. C; 3. D; 4. C; 5. B; 6. A; 7. D; 8. C; 9. B; 10. A; 11. D; 12. C; 13. B; 14. A; 15. C