In one hour, a boat goes 14 km/hr along the stream and 8 km/hr against the stream. The speed of the boat in still water (in km/hr) is:
Choices.
A) 10	B) 11	C) 12	D) 15	E) 14
Let speed of the boat in still water = a and speed of the stream = b   Then   a + b = 14   a - b = 8   Adding these two equations, we get 2a = 22   =&gt; a = 11   ie, speed of boat in still water = 11 km/hr   Answer is 11.
<result>B</result>
In one hour, a boat goes 14 km/hr along the stream and 8 km/hr against the stream. The speed of the boat in still water (in km/hr) is: