Question 726511
You head downstream on a river in an outboard.
 The current is flowing at a rate of 1.50 m/s.
Convert m/s to km/hr
{{{(1.5*3600)/1000}}} = 5.4 km/hr is the current
: 
After 30 min, you find that you have traveled 24.3 km.
Effective speed: 2 * 24.3 = 48.6 km/hr
Boat speed in still water 48.6 - 5.4 = 43.2 km/hr
:
 How long will it take you to travel back upstream to your original point of departure?
{{{24.3/((43.2-5.4))}}} = .643 hrs; .643*60 = 38.57 min to return