Question
The ratio of the speed of a boat in still water to the
speed of the stream is 4:1. If the boat takes 10 hours to cover 240 km downstream, find the total time taken by the boat to cover 180 km upstream and 180 km downstream.Solution
ATQ, Let the speed of the boat in still water be 4x km/h and the speed of the stream be x km/h. From the downstream trip, 
Speed of boat in still water = 4x = 16 km/h Speed of stream = x = 4 km/h Time taken to cover 180 km upstream and 180 km downstream: 
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