A man takes 2.2 times as long to row a distance upstream as to row the same distance downstream. If he can row 55 km downstream in 2 hour 30 minutes, what is the speed of the boat in the still water?

• ক 18 km/hr
• খ 12 km/hr
• গ 10 km/hr
• ঘ 16 km/hr ✅ সঠিক উত্তর