SOLUTION: A boat traveled 336 miles downstream and back. The trip downstream took 12 hours. The trip back took 14 hours. What is the speed of the boat in still water? What is the speed of t

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A boat traveled 336 miles downstream and back. The trip downstream took 12 hours. The trip back took 14 hours. What is the speed of the boat in still water? What is the speed of t      Log On


   



Question 292873: A boat traveled 336 miles downstream and back. The trip downstream took 12 hours. The trip back
took 14 hours. What is the speed of the boat in still water? What is the speed of the current?
12)

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A boat traveled 336 miles downstream and back.
The trip downstream took 12 hours.
The trip back took 14 hours.
What is the speed of the boat in still water?
:
Let s = boat speed in still water
Let c = speed of the current
then
(s-c) = effective speed upstream
(s+c) = effective speed downstream
:
Write two distance equations; dist = time * speed
:
14(s-c) = 336
12(s+c) = 336
:
Simplify; divide the 1st eq by 14, and the 2nd eq by 12, results
s - c = 24
s + c = 28
------------Addition eliminates c, find s
2s = 52
s = 52%2F2
s = 26 mph in still water
:
:
What is the speed of the current? we know: s + c = 28, replace s:
26 + c = 28
c = 28 - 26
c = 2 mph current