<span>If Mary is rowing at 3.5 m/s then it will take her 190 m divided by 3.5 m/s or about 54 secs to cross the river. If the river is flowing at 1.3 m/s then in 54 secs she will be carried 54 x 1.3 or around 70.5 meters downstream when she lands on the opposite shore.</span>
