- A15 h
- B12 h
- C18 h
- D9 h
Step-by-Step Solution
After 3 h: full. Net rate ; takes 12 h. Total = 15 h. (12 h forgets the first 3.)
Answer: A) 15 h
An inlet can fill a tank in 9 hours. After 3 hours of filling, an outlet that empties the full tank in 18 hours is opened by mistake. How long in total does the tank take to fill?
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