Pipe A fills a tank in 16 minutes and pipe B empties it in 24 minutes. With both running from the start, after how many minutes should B be shut off so the tank fills in 30 minutes?
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Answer: D. None of these
Explanation
Pipe A fills a tank in sixteen minutes while pipe B empties it in twenty-four minutes. Running both from the start and shutting off B to fill the tank in thirty minutes requires calculation. Solving the fractional rate equation yields a value not matching options A, B, or C, making none of these correct. Pipe and cistern problems treat filling rates as positive fractions and emptying rates as negative fractions. Algebraic equations track cumulative water volume over specified running times before shut-off events. Calculating exact minutes for valve closures ensures tanks reach full capacity at target times.
Water treatment plants and industrial plumbing systems use flow rate calculations to manage tank levels. Hydraulic engineers program automated valve shut-off timers based on pipe filling and emptying speeds. Aptitude test questions use none of these options to catch calculation errors in competitive exams. Option A suggests twenty minutes, which fails the thirty-minute total fill time equation. Option B proposes twenty-four minutes, resulting in an incorrect final water volume level. Option C suggests twenty-three minutes, an intermediate value not supported by the rate formulas.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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