In one hour, a boat goes 15 km along the stream and 5 km against the stream. The speed of the boat in still water (in km/hr) is: Choose the most appropriate option
A) 2
B) 4
C) 10
D) 12
E) 15
Sol.   Speed in still water = 1/2 (15+5) kmph = 10 kmph.   Answer 10
<result>C</result>
In one hour, a boat goes 15 km along the stream and 5 km against the stream. The speed of the boat in still water (in km/hr) is: