A river 400m wide is flowingat a rate

A river 400m wide is flowing at a rate of 2.0 m/s.a boat      is sailing at a velocity of 10 m/s with respect to the water,     in a direction perpendicular to the river.(a) fibd the time taken    by the boat to reach the opposite bank.(b)how far from the point      directly opposite to the starting point does the boat reach the opposite bank?

  A river 400m wide is flowing at a rate of 2.0 m/s.a boat      is sailing at a velocity of 10 m/s with respect to the water,     in a direction perpendicular to the river.(a) fibd the time taken    by the boat to reach the opposite bank.(b)how far from the point      directly opposite to the starting point does the boat reach the opposite bank?