In one hour a boat goes 6 km/hr along the stream and 14 km/hr against the stream. The speed of the boat in still water(in km/hr) is?
Choose the correct choice from the following choices:  A) 20 km/hr  B) 10 km/hr  C) 15 km/hr  D) 30 km/hr  E) 40 km/hr
Explanation:   Speed of boat in still water = 1/2 (Speed downstream + speed up stream)   = 1/2 (6 + 14) = 1/2 x 20   = 10 km/hr   Answer: Option 10 km/hr
<result>B</result>
In one hour a boat goes 6 km/hr along the stream and 14 km/hr against the stream. The speed of the boat in still water(in km/hr) is?