- A24 min
- B min
- C18 min
- D6 min
Step-by-Step Solution
Net emptying per minute; min. (6 min forgets that A keeps filling.)
Answer: C) 18 min
A cistern is three-quarters full. Pipe A can fill the empty cistern in 12 minutes and pipe B can empty the full cistern in 8 minutes. If both are opened, how long will it take to empty the cistern?
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