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Area and volume: California T2 water treatment operator math

Pipe, tank, basin, trench and wall areas and volumes; force on a valve.

Below are 3 worked examples. Each answer is computed with the formulas and constants on the CA Exam Conversion Sheet (revised 4/30/2026), and the solution names the line it uses.

Formulas from the sheet for this topic

Example 1. A cylindrical storage tank is 110 ft in diameter with water 13 ft deep. How many gallons does it hold?

  1. A) 1,850,000 gal
  2. B) 1,030,000 gal
  3. C) 924,000 gal
  4. D) 3,690,000 gal
Show the answer and worked solution

Answer: C) 924,000 gal

1. Cylinder Volume (Gal) = .785 × D² × Height × 7.48 [Sheet p.1, Area and Volume: "Cylinder Volume (Gal) = .785 x D2 x Height or Length (Ft) x 7.48"]. 2. = .785 × 110 × 110 × 13 × 7.48 = 923,634 gal. 3. Answer: 924,000 gal (rounded to 3 significant figures).

Source: CA Exam Conversion Sheet (Revised 4/30/2026), p.1, Area and Volume: "Cylinder Volume (Gal) = .785 x D2 x Height or Length (Ft) x 7.48"

Example 2. A cylindrical storage tank is 50 ft in diameter with water 22 ft deep. How many gallons does it hold?

  1. A) 6,460 gal
  2. B) 162,000 gal
  3. C) 43,200 gal
  4. D) 323,000 gal
Show the answer and worked solution

Answer: D) 323,000 gal

1. Cylinder Volume (Gal) = .785 × D² × Height × 7.48 [Sheet p.1, Area and Volume: "Cylinder Volume (Gal) = .785 x D2 x Height or Length (Ft) x 7.48"]. 2. = .785 × 50 × 50 × 22 × 7.48 = 322,949 gal. 3. Answer: 323,000 gal (rounded to 3 significant figures).

Source: CA Exam Conversion Sheet (Revised 4/30/2026), p.1, Area and Volume: "Cylinder Volume (Gal) = .785 x D2 x Height or Length (Ft) x 7.48"

Example 3. A rectangular basin is 95 ft long and 21 ft wide, with water 7.5 ft deep. How many gallons does it hold?

  1. A) 112,000 gal
  2. B) 933,000 gal
  3. C) 125,000 gal
  4. D) 15,000 gal
Show the answer and worked solution

Answer: A) 112,000 gal

1. Rectangular Basin (Gal) = L × W × H × 7.48 [Sheet p.1, Area and Volume: "Rectangular Basin (Gal) = Length (Ft) x Width (Ft) x Height (Ft) x 7.48"]. 2. = 95 × 21 × 7.5 × 7.48 = 111,920 gal. 3. Answer: 112,000 gal (rounded to 3 significant figures).

Source: CA Exam Conversion Sheet (Revised 4/30/2026), p.1, Area and Volume: "Rectangular Basin (Gal) = Length (Ft) x Width (Ft) x Height (Ft) x 7.48"

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Practice all 74 area and volume problems for CA T2 Math

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