<PRE><B>Question 302176</B>
upstream it takes 51 minutes

let the speed of current be x mph

speed of boat will be 50-x

speed * time = distance 
=(50-x) * 51/60 

downstream it takes 49 minutes

speed of boat = 50+x

Distance = (50+x)*49/60

Since the distance traveled both ways is the same 

(50-x)*51/60 = (50+x)*49/60

(50-x)*51 = (50+x)*49

2550-51x=2450+49x

2550-2450=51x+49x

100=100x

x=1 mph which is the speed of the current

Ananth

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