SOLUTION: If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hours, the rate of the river and the rate of the boat in still water respectively are ?

Algebra ->  Human-and-algebraic-language -> SOLUTION: If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hours, the rate of the river and the rate of the boat in still water respectively are ?      Log On


   



Question 65062: If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hours, the rate of the river and the rate of the boat in still water respectively are ?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If a boat goes downstream 72 miles in 3 hours and upstream 60 miles in 6 hours, the rate of the river and the rate of the boat in still water respectively are ?
--------------------
Let b be the boat rate; s be the stream rate
----------------
Downstream DATA:
distance=72 miles ; time = 3 hrs ; rate= d/t=72/3=24 mph
--------------
Upstream DATA:
distance = 72 miles ; time = 6 hrs; rate =d/t=72/6 = 12 mph
---------------
EQUATIOn:
b+s=24
b-s=12
2b=36
b=18 mph (boat speed in calm water)
18+s=24
s=6 mph (stream speed)
-----------
Cheers,
Stan H.