SOLUTION: A motor boat takes 5 hrs to travel 300 mi going upstream. The return trip takes 2hrs. going downstream. What is the rate of the boat in still water and what is the rate of the curr

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Question 374768: A motor boat takes 5 hrs to travel 300 mi going upstream. The return trip takes 2hrs. going downstream. What is the rate of the boat in still water and what is the rate of the current?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let rate of boat in still water be x mph
rate of current be y
..
downstream speed = x+y
upstream rate = x-y
..
t = d/r
upstream
5 = 300/(x-y)
5(x-y)=300
5x-5y=300
/5
x-y=60.......................1
downstream
2= 300/(x+y)
2(x+y)=300
2x+2y=300
/2
x+y =150.....................2
...
Add 1 & 2
2x=60+150
2x=210
/2
x= 105 mph rate of boat in still water
x-y =60
plug x
105-y=60
y = 105-60
y=45 mph
...
m.ananth@hotmail.ca