The speed of the boat in still water is 40% less than

Solution

Let’s assume the speed of boat in still water and the speed of stream are ‘B’ and ‘C’ respectively. The speed of the boat in still water is 40% less than the speed of the boat in downstream. B = (100-40)% of (B+C) B = 60% of (B+C) B = 0.6(B+C) If the speed of stream is 16 km/h. B = 0.6(B+16) B = 0.6B+96 B-0.6B = 9.6 0.4B = 9.6 B = 24 km/h The time taken by the boat to cover 468 km distance in upstream is (t+0.5) hours. 468/(t+0.5) = (B-C) Put the value of ‘B’ and ‘C’ in the above equation. 468/(t+0.5) = (24-16) 468/(t+0.5) = 8 468/8 = (t+0.5) (t+0.5) = 58.5 t = 58.5-0.5 Value of ‘t’ = 58