The speed of a motor-boat is that of the current of water as 36:5. The boat goes along with the current in 5 hours 10 minutes. It will come back in:

• ক 12 hours 10 minutes
• খ 5 hours 50 minutes
• গ 6 hours 50 minutes ✅ সঠিক উত্তর
• ঘ 6 hours