SOLUTION: A boat travels 60 miles downstream in The same time it takes to go 36 miles upstream. The speed of The boat in still water is 15 mph greater than The speed of The current. Find Th

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Question 550591: A boat travels 60 miles downstream in The same time it takes to go 36 miles upstream. The speed of The boat in still water is 15 mph greater than The speed of The current. Find The speed of The current.
Found 2 solutions by mananth, ankor@dixie-net.com:
Answer by mananth(16949) (Show Source):
You can put this solution on YOUR website!
let speed of current be x
speed of boat be y
y-x=14..........(1)
60/(y+x)= 36/(y-x)
60(y-x)=36(y+x)
/12
5(y-x)=3(y+x)
5y-5x=3y+3x
2y-8x=0
/2
y-4x=0..........(2)
multiply (1) by -4
-4y+4x=-56
add this equation to (2)
-3y=-56
y=18.66 mph
y-x=14
18.66-x=14
x=4.66 mph

Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
A boat travels 60 miles downstream in The same time it takes to go 36 miles upstream.
The speed of The boat in still water is 15 mph greater than The speed of The current.
Find The speed of The current.
:
Let x = speed of the current
and
(x+15) = speed of the boat in still water
then
x + (x+15) = 2x+15; the effective speed down stream
and
(x+15) - x = 15 mph; the effective speed upstreams
:
Write a time equation; time = dist/speed
:
downstr time = upstr time
=
Cross multiply
36(2s+15) = 60 * 15
72s + 540 = 900
72s = 900 - 540
72s = 360
s =
s = 5 mph is the rate of the current
:
:
Confirm this solution,
The speed of the boat in still water = 15 + 5 = 20 mph
The speed with the current: 20 + 5 = 25 mph
The speed against the current: 20 - 5 = 15 mph
:
Find the time each way, they should be equal
60/25 = 2.4 hrs
36/15 = 2.4