Two boats, A and B, move away from a
buoy anchored at the middle of a river along the mutually perpendicular
straight lines: the boat A along the river, and the boat B across the river.
Having moved off an equal distance from the buoy the boats returned. Find the
ratio of times of motion of boats ta/tb if the velocity of
each boat with respect to water is r) = 1.2 times greater than
the stream velocity.