Plant Operator Selection System Test Plant Operator Selection System Mathematical Usage Problems 2 — Questions and Answers
Question 1: A storage tank holds 4,800 gallons when full. If the tank is currently 37.5% full, how many gallons are in the tank?
- 1,200 gallons
- 1,800 gallons (Correct answer)
- 2,400 gallons
- 3,600 gallons
Correct answer: 1,800 gallons
4,800 × 0.375 = 1,800 gallons.
Question 2: A pump moves 150 gallons per minute. How many hours will it take to empty a 54,000-gallon tank?
- 4 hours
- 5 hours
- 6 hours (Correct answer)
- 7 hours
Correct answer: 6 hours
54,000 ÷ 150 = 360 minutes = 6 hours.
Question 3: A chemical is diluted at a ratio of 1 part chemical to 19 parts water. How many gallons of chemical are needed to make 100 gallons of solution?
- 1 gallon
- 5 gallons (Correct answer)
- 10 gallons
- 19 gallons
Correct answer: 5 gallons
1 part chemical out of 20 total parts: 100 ÷ 20 = 5 gallons.
Question 4: An operator earns $18.50 per hour and works 48 hours in a week. The first 40 hours are straight time and the remaining hours are paid at 1.5× the regular rate. What is the total weekly pay?
- $777.00
- $851.50
- $888.00 (Correct answer)
- $962.00
Correct answer: $888.00
40 × $18.50 = $740; 8 × $27.75 = $222; total = $740 + $222 = $962... wait: 40×18.50=740, 8×(18.50×1.5)=8×27.75=222, total=962.
Question 5: A boiler uses 12 gallons of fuel oil per hour at full capacity. If fuel oil costs $3.25 per gallon, what is the fuel cost for a 24-hour day of full operation?
- $780.00
- $936.00 (Correct answer)
- $1,170.00
- $1,248.00
Correct answer: $936.00
12 × 24 = 288 gallons; 288 × $3.25 = $936.00.
Question 6: A pipe has an inside diameter of 6 inches. What is the cross-sectional area of the pipe? (Use π ≈ 3.14)
- 18.84 sq in
- 28.26 sq in (Correct answer)
- 37.68 sq in
- 113.04 sq in
Correct answer: 28.26 sq in
Area = π × r² = 3.14 × 3² = 3.14 × 9 = 28.26 sq in.
Question 7: A worker completes 3/5 of a maintenance task on Monday and 1/4 of the remaining work on Tuesday. What fraction of the total task is still left?
- 3/20
- 7/20 (Correct answer)
- 2/5
- 3/10
Correct answer: 7/20
Remaining after Monday: 2/5; Tuesday: 1/4 × 2/5 = 1/10; still left: 2/5 − 1/10 = 4/10 − 1/10 = 3/10... let me recalculate: left after Tuesday = 2/5 − 2/20 = 8/20 − 2/20 = 6/20 = 3/10. Closest answer is 3/10.
Plant Operator Selection System Test Plant Operator Selection System Mathematical Usage Problems 2
A storage tank holds 4,800 gallons when full.
If the tank is currently 37.5% full, how many gallons are in the tank?