- A6 min
- B22.5 min
- C15 min
- D7.5 min
Step-by-Step Solution
A runs all 30 min: . B must supply , which takes min. (22.5 min is how long before the end B is shut.)
Answer: D) 7.5 min
Pipes A and B fill a tank in 36 and 45 minutes. Both are opened together. After how many minutes must B be turned off so that the tank is full in exactly 30 minutes?
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