Solving Applied Problems with 2 Equations

Question

Alvin paddled for 2 hours with a 6-km/h current to reach a campsite. The return trip against the same current took 8 hours.

Find the speed of the boat in still water.

Answer 1

d = rt

 

The distance going is equal to the distance returning.  Let x=speed of boat.

 

going                           returning

 

d =(x + 6)2                   d=(x - 6)8

 

2x + 12 = 8x - 48

 

-6x = -60

 

x = 10 km/hr