SOLUTION: A motorboat went 10 miles upstream for 60 minutes. The return trip took only 30 minutes. Assume that the speeds of the boat and current were constant during this round trip. Find e

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Question 865131: A motorboat went 10 miles upstream for 60 minutes. The return trip took only 30 minutes. Assume that the speeds of the boat and current were constant during this round trip. Find each speed of the boat and current as mile per hour.
Found 2 solutions by lwsshak3, Alan3354:
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
A motorboat went 10 miles upstream for 60 minutes. The return trip took only 30 minutes. Assume that the speeds of the boat and current were constant during this round trip. Find each speed of the boat and current as mile per hour.
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let x=speed of boat
let c=speed of current
x+c=speed of boat with current
x-c=speed of boat against current
travel time*speed=distance
60 min=1hr
30 min=.5 hr
..
1*(x-c)=10
.5*(x+c)=10
..
x-c=10
.5x+.5c=10
..
x-c=10
x+c=20
add
2x=30
x=15
c=x-10=5
speed of boat=15 mph
speed of current=5 mph

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Find the speed up and downstream
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up = 10 mi/hr
down = 20 mi/hr
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The boat speed is the average = 15 mi/hr
--
The current is the difference between boat speed and groundspeed = 5 mi/hr