SOLUTION: The speed of a boat in still water is 4 miles per hour. If the boat travels 5 miles downstream in the same amount of time it takes to travel 2.5 miles upstream, what is the speed o

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Question 509037: The speed of a boat in still water is 4 miles per hour. If the boat travels 5 miles downstream in the same amount of time it takes to travel 2.5 miles upstream, what is the speed of the current?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Boat speed = 4 mph
current speed = x mph
wind speed
speed against current 4 - x
speed with current 4 + x

Distance against current 2.5 m
Distance with current 5 m

t=d/r time against = time with
2.5/(4-x)=5/(4+x)
2.5(4+x)=5(4-x)
10+2.5x =20-5x
5x+2.5x =10
7.5x=10
/ 7.5
x =1.33 mph current speed