The trench pump log shows a pump removing 21 gallons per minute for 31 minutes. How many gallons are removed during the run?
Correct Answer
A) 651 gallons.
Flow volume is rate times time: 21 gallons per minute for 31 minutes equals 651 gallons.
Why This Is the Correct Answer
Flow volume is rate times time: 21 gallons per minute for 31 minutes equals 651 gallons.
Why the Other Options Are Wrong
Option B: 620 gallons total.
620 gallons total. is below the supported result for plumbing flow calculation; it likely omits allowance, conversion, coverage, or final round-up.
Option C: 672 gallons total.
672 gallons total. is above the supported result for plumbing flow calculation; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Option D: 700 gallons total.
700 gallons total. is above the supported result for plumbing flow calculation; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Memory Technique
Estimating Temporary takeoff: count the condition before counting the package.
Reference Hint
Study anchor (closed-book): memorize Plumbing flow calculation from California Plumbing Code, California Code of Regulations Title 24. / Title 24 California Plumbing Code pump capacity concepts; know the rule or calculation trigger without relying on exam-room lookup.
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