SOLUTION: A sightseeing boat travels 3 hrs. on a trip downstream with a 2.5mph current. The return trip against the same current takes 3.5 hrs. Find the speed of the boat in still water.

Click here to see ALL problems on Linear-equations

Question 181807: A sightseeing boat travels 3 hrs. on a trip downstream with a 2.5mph current. The return trip against the same current takes 3.5 hrs. Find the speed of the boat in still water.
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
A sightseeing boat travels 3 hrs. on a trip downstream with a 2.5mph current.
The return trip against the same current takes 3.5 hrs.
Find the speed of the boat in still water.
:
Let s = boat speed in still water
then
(s+2.5) = speed down-stream
and
(s-2.5) = speed up-stream
:
Distance of each trip is the same. Write a dist equation: dist = time * speed
:
Dist up = dist down
3.5(s-2.5) = 3(s+2.5)
:
3.5s - 8.75 = 3s + 7.5
:
3.5s - 3s = 7.5 + 8.75
:
.5s = 16.25
s =
s = 32.5 mph in still water
:
:
Check solution by finding the distance of each:
3.5 * 30 = 105 mi
3.0 * 35 = 105 mi