A steamer goes downstream from one port to another in 4 hours, it covers the same distance upstream in 5 hours. If the speed of the stream is 2km/hr,the distance between the two parts is_______?
Q1. A steamer goes downstream from one port to another in 4 hours, it covers the same distance upstream in 5 hours. If the speed of the stream is 2km/hr,the distance between the two parts is_______?
Answer: 80 km
Explanation: Let still-water speed = v. Downstream: 4(v+2) = distance; upstream: 5(v−2) = same distance. Setting equal: 4v+8 = 5v−10 → v = 18 km/h. Distance = 4 × 20 = 80 km.