James can row 14 km downstream in a river in 2 hours. He takes 7 hours to go back. Find the speed of the current and the speed of James in still water. Solution d = rt c = speed of current, r = rowing speed 14 = (r+c)*2 = (r-c)*7 2r+2c=14 7r-7c=14 ------- r+c=7 Eqn 1 div by 2 r-c=2 Eqn 2 div by 7 ----- Add equations 2r = 9 r = 4.5 kph c = 2.5 kph.