Solution

Let’s assume the speed of boat in still water and the speed of stream are ‘B’ and ‘C’ respectively. The ratio between the time taken by a boat to cover a certain distance in upstream and the same distance in downstream is 5:1 respectively. Let’s assume the distance covered in each stream by the boat is ‘d’ km. [d/(B-C)] / [d/(B+C)] = 5/1 (B+C)/(B-C) = 5/1 (B+C) = 5(B-C) B+C = 5B-5C 5B-B = 5C+C 4B = 6C 2B = 3C If the speed of the stream is 60 km/h. 2B = 3x60 = 180 B = 90 The same boat can cover the same distance which was covered in upstream in still water in (35/3) hours. d/90 = 35/3 d/30 = 35 d = 35x30 d = 1050 km The distance covered by the boat in downstream = 1050 km