Two pipes A and B can fill a tank in 24 and 32 min, respectively. If both the pipes are opened together, after how much time pipe B should be closed so that the tank is full in 9 min?

• ক 30 min
• খ 25 min ✅ সঠিক উত্তর
• গ 40 min
• ঘ 10 min
• 5 20 min