<PRE><B>Question 1176815</B>
let rate of the boat in still water be x km/h
 and  the rate of the current be y km/h

Upstream speed = x-y

Time = D/S

165/(x-y) = 3
3x-3y=165 -----------(1)

Downstream speed = x+y 
207/(x+y) =3
3x+3y= 207-----------(2)

Add equations (1) &amp; (2)
6x=207+165
6x = 372
x= 62 
 speed of boat in still water= 62 km/h
Plug x to get y

3x-3y=165
186-3y =165

3y= 21
y=7

Speed of current is 7 km/h













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