SOLUTION: A tugboat goes 100 miles upstream in 10 hours. The return trip takes 5 hours. Find the speed of the tugboat without a current and the speed of the current.

Question 619027: A tugboat goes 100 miles upstream in 10 hours. The return trip takes 5 hours. Find the speed of the tugboat without a current and the speed of the current.
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
A tugboat goes 100 miles upstream in 10 hours. The return trip takes 5 hours. Find the speed of the tugboat without a current and the speed of the current.
:
let s = speed in still water
Let c = speed of the current
then
(s-c) = effective speed upstream
and
(s+c) = effective speed downstream
:
Write distance equation for each way. (dist = time * speed
10(s-c) = 100
5(s+c) = 100
Simplify both equations, divide the 1st equation by 10, divide the 2nd equation by 5, results:
s - c = 10
s + c = 20
-----------Adding eliminates c find s
2s = 30
s = 30/2
s = 15 mph boat speed in still water
:
You can find the current, check the solutions in the original equations
:

RELATED QUESTIONS
a tugboat goes 100 miles upstream in 10 hours. the return trip downstream takes 5 hours.... (answered by mananth)

a tugboat goes 180 miles upstream in 10 hours. the return trip downstream takes 5 hours.... (answered by scott8148)

A tugboat goes 180 miles upstream in 10 hours. The return trip downstream takes 5... (answered by checkley79)

A tugboat goes 120 miles upstream in 10 hours. The return trip downstream takes 5 hours.... (answered by mananth)

A tugboat goes 100 miles upstream in 10 hours. The return trip downstream takes 5 hours.... (answered by mananth)

A tugboat goes 120 miles upstream in 15 hours. The return trip down stream takes 10... (answered by Alan3354)

A tugboat goes 120 miles upstream in 15 hours. The return trip downstream takes 5 hours.... (answered by mananth)

A tugboat goes 180 miles upstream in 15hours. The return trip downstream takes 10 hours.... (answered by josmiceli)

a tugboat goes 180 miles upstream in 10 hours. The return trip downstream takes 5 hours. (answered by Alan3354)