Calculate the speed of a boat in still water (in km/hr) if in one hour, the boat goes 13 km/hr downstream and 10 km/hr upstream.
Options.
A) 3 kmph
B) 9 kmph
C) 4 kmph
D) 8 kmph
E) 6 kmph
Speed in still water = (13 + 5)1/2 kmph = 9 kmph.   answer :9 kmph
<result>B</result>
Calculate the speed of a boat in still water (in km/hr) if in one hour, the boat goes 13 km/hr downstream and 10 km/hr upstream.