Question

A speed of boat in still water is 11km/hr. It can go 12 km upstream and return downstream to the original point in 2hr 45 minutes. Find the speed of the stream.

Answer 1

Solution
Solve
Speed of the boat in still water = 11 km/hr
Let the speed of stream = x km/hr
speed upstream = (11-x) km/hr
speed of downstream = (11+x) km/hr

According to the given condition
{12/(11+x)}+{12/(11-x)} = 11/4

Solve

Speed of the stream = 5 km/hr