Could someone me with this kinematics question? :

a swimmer heads directly across a river, swimming at 1.6 m/s relative to the water. she
arrives at a point 40 m downstream from the point directly across the river, which is 80 m
wide.

a) what is the speed of the river current?

b) what is the swimmer's speed relative to the shore?

c) in what direction should the swimmer head to arrive at the point directly opposite her
starting point?

d) how long would it take to cross the river swimming in the direction found in (c)?