A man can row 7.5 km/hour in still water & he finds that it takes him twice aslong to row up as to row down the river. Find the rate of stream?	Choose the correct choice from the following answers:
A) 2 km/hr
B) 2.5 km/hr
C) 3 km/hr
D) 4 km/hr
E) 4.3 km/hr
Given that, time taken to travel upstream = 2 × time taken to travel downstream   When distance is constant, speed is inversely proportional to the time   Hence, 2 × speed upstream = speed downstream   Let speed upstream =x   Then speed downstream =2x   we have, 12(x+2x) = speed in still water   ⇒12(3x)=7.5⇒3x=15⇒x=5   i.e., speed upstream = 5 km/hr   Rate of stream =12(2x−x)=x2=52=2.5 km/hr   2.5 km/hr
<result>B</result>
A man can row 7.5 km/hour in still water & he finds that it takes him twice aslong to row up as to row down the river. Find the rate of stream?