Pipes A and B fill a cistern in 8 and 24 minutes respectively. Operating in alternating minutes, how long will it take to fill the cistern?
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Answer: B. 12 min
Explanation
The correct answer is twelve minutes for the alternating pipes to fill the cistern. Pipe A fills one-eighth and pipe B fills one-twenty-fourth of the cistern each minute. Alternating operation cycles fill specific fractions until the total volume reaches one. Alternating work problems require calculating cumulative output over repeating time cycles. In two minutes, pipe A and pipe B together fill one-sixth of the total cistern volume. Repeating this two-minute cycle six times results in total completion after twelve minutes.
Intermittent pump operation schedules are used in industrial irrigation to manage power loads. Alternating mechanical systems in manufacturing prevent overheating during continuous production. Fluid dynamics applications often involve cyclic valve operations to regulate tank levels. Option A underestimates the total time by only calculating half of the required cycles. Option C results from miscounting the alternating cycle repetitions needed for completion. Option D fails to align the fractional filling cycles with the total volume requirement.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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