In one hour, a boat goes 15 km/hr along the stream and 11 km/hr against the stream.
In one hour, a boat goes 15 km/hr along the stream and 11 km/hr against the stream. The speed of the boat in still water (in km/hr) is:
Answer/Solution
13 kmph
Steps/Work
Explanation:
Let the speed downstream be a km/hr and the speed upstream be b km/hr, then
Speed in still water =1/2(a+b) km/hr
Rate of stream = 1/2(a−b) km/hr
Speed in still water = 1/2(15+11) kmph = 13 kmph.
Answer: Option B
Let the speed downstream be a km/hr and the speed upstream be b km/hr, then
Speed in still water =1/2(a+b) km/hr
Rate of stream = 1/2(a−b) km/hr
Speed in still water = 1/2(15+11) kmph = 13 kmph.
Answer: Option B