SOLUTION: Please help. Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4-mph current, it took her 20 minutes longer to get there than to return. How fa

Question 178714: Please help.
Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4-mph current, it took her 20 minutes longer to get there than to return. How fast will her boat go in still water?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let the speed of her boat in still water =
Let the speed of the current =
Against the current:

with the current:

-------------------------
given:
mi
mi
mi/hr
hr (20 min is 20/60 of an hour)
--------------------------
Now I can write:
(1)
(2)
I have 2 equations and 2 unknowns, so it should be solvable
Since both (1) and (2) = , I'll set the right sides
equal to eachother

Divide both sides by

Substitute this value of into (2)
(2)
(2)

Her boat will go 11.66 mi/hr in still water
check answer:
(2)
(2)

hrs

hrs
------------------------
(1)

close enough
(2)

close enough
And, also should be 20 min
longer than

min close enough