A steamboat goes across a lake and comes back (1) On a quiet day when the water is still and on a rough day when there is uniform current so as to help the journey onwards and to impede journey back, if the speed of the launch on both days was same, in which case it will complete journey in lesser time

(1) case (1)

(2) case (2)

(3) Same in both

(4) Nothing can be predicted