A man can row 30 km downstream and 20 km upstream in 4 hours. He can row 45 km downstream and 40 km upstream in 7 hours. Find the speed of man in still water? September 23, 2025 by Admin A. 15 kmph B. 10 kmph C. 12 kmph D. 12.5 kmph ✅ The correct answer is option D. 12.5 kmph.