SOLUTION: A boat goes 540 miles downstream in the same time it can go 450 miles upstream. The speed of the current is 4 miles per hour. Find the speed of the boat in still water.
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Question 237085: A boat goes 540 miles downstream in the same time it can go 450 miles upstream. The speed of the current is 4 miles per hour. Find the speed of the boat in still water.
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
Let 
represent the speed of the boat in still water.
Downstream trip:
t\ \ \Rightarrow\ \ \frac{540}{r+4}\ =\ t)
Upstream trip:
t\ \ \Rightarrow\ \ \frac{450}{r-4}\ =\ t)
So
Cross-multiply:
\ =\ 450r\ +\ 4(450))
)
\ =\ 44)
John
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