SOLUTION: The speed of a stream is 4mph. A boat travels 8 miles upstream in the same time it takes to travel 16 miles downstream. What is the speed of the boat in the water?

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Question 350769: The speed of a stream is 4mph. A boat travels 8 miles upstream in the same time it takes to travel 16 miles downstream. What is the speed of the boat in the water?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let the speed of boat in still water be x mph
speed of current 4 mph
..
speed upstream = x-4 mph
speed downstream = x+4
..
distance = 8 miles upstream
time upstream = 8/x-4
..
time downstream = 16/x+4)
..
both the times are same
..
8/(x-4) = 16/(x+4)
8(x+4)=16(x-4)
8x+32=16x-64
16x-8x=64+32
8x=96
x= 12 mph speed of boat in still water