SOLUTION: A boat glides downstream for 12 hours. Because the stream's current, it takes the boat 22 hours to go back upstream. If the speed of the river is 5mph, find the speed of the boat i

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A boat glides downstream for 12 hours. Because the stream's current, it takes the boat 22 hours to go back upstream. If the speed of the river is 5mph, find the speed of the boat i      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1006736: A boat glides downstream for 12 hours. Because the stream's current, it takes the boat 22 hours to go back upstream. If the speed of the river is 5mph, find the speed of the boat in still water.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +d+ = distance in mi that boat drifts downstream
+d+ is also the distance the boat goes back upstream
---------------------------------------------
The speed of the river is +5+ mi/hr
d+=+r%2At+
+t+=+12++ hrs
+d+=+5%2A12+
+d+=+60+ mi
--------------
Going back upstream,
let +s+ = the speed of the boat in mi/hr in still water
+s+-+5+ = the speed of the boat going upstream
+60+=+%28+s+-+5+%29%2A22+
+60+=+22s+-+110+
+22s+=+170+
+s+=+7.727+
The speed of the boat in still water is 7.727 mi/hr