The speed of a boat in still water 10 km/hr. If it can travel 26 km downstream and 14 km upstream in the same time, the speed of the stream is:
a) 2 km/hr
b) 2.5 km/hr
c) 3km/hr
d) 4 km/hr
Correct option: c) 3km/hr
Explanation:
let the speed of the stream be x km ph.
Speed downstream =(10+x) km ph ;speed upstream =(10-x) km ph 26/(10+x) =14/(10-x) therefore 40x=120 and x=3 km ph
