Question

the speed of a boat in still water is 8 km / 1hr it can go 15 km upstream and 22 km downstream in 5hr. find the speed of the stream

Answer 1

Kishore answered 4 year(s) ago
The speed of a boat in still water is 8 km/hr
The speed of a boat in still water is 8 km/hr. If it takes the same time in going 20 km downstream as it takes in going 12 km upstream. Find the speed of the water of the river.




Let the speed of water in the river be x km/hr
Speed of boat upstream = (8 – x) km/hr
Speed of boat downstream = (8 + x) km/hr
Distance travelled downstream = 20 km
Recall that time taken = (Distance)/(Speed)
Time taken to travel downstream = 20/(8 + x)
Distance travelled upstream = 12 km
Time taken to travel upstream = 12/(8 – x)
Given time taken to travel downstream = time taken to travel upstream

Thus speed of water in the river is 2 km/hr.