<PRE><B>Question 516862</B>
Let 
Speed of boat = b
speed of current = c

Upstream
Boat against the Current
b-c=48/6= 8 ..............(1)
Downstream
Boat with the Current
b+c=48/3 = 16 .............(2)

Add (1) and (2)
b-c= 8 ..............(1)
b+c= 16 .............(2)
2b=24
2b/2=24/2
b=12
Put the value of b in (2)
b+c=16
12+c=16
c=16-12
c=4


Speed of boat = b = 12 miles/hour
speed of current = c = 4 miles/hour



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