SOLUTION: A motorboat takes 4 hours to travel 320 km going upstream. the return trip takes 2 hours going downstream. What is the rate of the boat in still water and what is the rate of the c

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Question 387690: A motorboat takes 4 hours to travel 320 km going upstream. the return trip takes 2 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Rate*Time=Distance
R%2At=D
.
.
.
Let the boat rate be B, the current rate C.
With the current,
%28B%2BC%292=320
1.B%2BC=160
Against the current,
%28B-C%294=320
2.B-C=80
Add the equations together,
B%2BC%2BB-C=160%2B80
2B=240
highlight%28B=120%29kph
Then use either equation to solve for C.
120%2BC=160
highlight%28C=40%29kph