<PRE><B>Question 309802</B>
let the speed of boat in still water be xmph.
then downstream speed will be x+4
time taken to travel 74 kms downstream = 74/x+4
.
Upstream speed will be x-4 mph.
time taken for traveling 37 miles = 37/x-4
.
both times are same.
.
74/x+4 = 37/x-4
74(x-4)=37(x+4)
74x-296= 37x + 148
37x=148+296
37x= 444
x= 444/37
x= 12 mph boat rate in still water



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