- A25 min
- B15 min
- C20 min
- D30 min
Step-by-Step Solution
B runs 40 min: . A filled , i.e. ran min. So it was closed min before the end. (15 min is how long A ran.)
Answer: A) 25 min
Pipes A and B fill a tank in 45 and 60 minutes. They are opened together, but A is closed before the tank is full, and the whole filling takes 40 minutes. How many minutes before the end was A closed?
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